‫محاضرات مادة وقاية الفم واالسنان‬
‫ قسم وقاية االسنان‬/ ‫ جنان محمد رشاد شهاب‬.‫د‬
Lecture one
Introduction to field of Dentistry
dentist, dental assistant and dental
technician
Dentistry: dentistry is one of the most demanding professions in terms of knowledge and skills
required, dealing with the treatment and prevention of dental diseases.
Dental public health:
Is that branch of Dentistry which deals with the prevention and control of dental diseases. These
procedures are done by the dental teams which include: the dentist, the dental assistant, the dental
hygienist and the dental laboratory technician.
Dental laboratory technician:
An individual trained to fabricate inlays, crowns, bridges, dentures splints and other items needed
for rebuilding a mouth.
The role of dental technician in different branches of Dentistry:
1-oral surgery: the role of technician in oral surgery includes:
a. formation of palatal splints after removal of impacted canine.
b. construction of abturators which are removable appliances designed to close an opening such as
cleft of hard palate or a gap produced after a tumor
removal.
c. construction of cast splints for treatment of fractures of facial bones.
d. form acrylic splints to close the socket of a hemophilic patient after
extraction.
e. rebasing and relining the denture after correction of pre-prosthetic abnormality in the
ridges.
f. formation of study cast for orthognathic surgery purposes.
2- Oral medicine:
The role of technician in oral medicine includes:
a. construction of bite raising appliances for T.M. joint disturbances.
b. correction of ill fitting dentures base to prevent denture stomatitis.
c. relief of sharp edges and long flanges of dentures to avoid trauma to the
oral mucosa.
3- Conservative Dentistry:
The role of technician includes:
a. formation of crowns and bridges technical laboratory work.
b. laboratory technical work of inlay.
c. laboratory technical work of ceramics and porcelain.
d. post crowns and post bridges.
e. anterior teeth veneers and facing,
4- Endodontic:
The role of technician is a construction of post crowns and post bridges.
5- Periodontology:
The role of technician includes:
a. construction of labial plates to avoid problems of bruxism.
b. construction of splints to fix mobile teeth.
c. consideration of periodontal health during construction of partial dentures.
6- Orthodontics:
The role of technician includes:
a. construction of orthodontic appliances and plates.
b. construction of palatal or mandibular expansion screw appliances.
c. construction of fixed appliances for orthodontic treatment.
7- Pedodontics:
The role of technician includes:
a. construction of space maintainers after early loss of deciduous teeth.
b. formation of splints for treatment of fractured or avulsed teeth.
c. crown and fixed bridges for the lost permanent teeth.
d. inlay fillings of teeth construction.
e. formation of post crowns for anterior root filled permanent teeth.
8- Prosthdontics:
The role of technician includes:
a. construction of complete denture.
b. construction of partial denture.
c. construction of chrome cobalt full or partial denture.
d. rebasing or relining of ill fitting dentures.
e. repair of broken dentures.
f. in some countries they have the right to take impressions and construct the
dental prosthesis independently of the dentist.
Lecture two
Preventive Dentistry, definition, the role of
dental specialist in prevention and the role
of
dental
assistant
in
prevention
Definition of Preventive Dentistry: Is that branch of Dentistry that deals with
maintaining maximum oral health for patients. Without prevention, Dentistry
becomes:
1- A continuous process of repair with all of its frustrations of endless expense,
discomfort, impaired dental function and ultimate failure.
2- It can fail to protect people from complications in other parts of the body as a
result of diseased dental and oral structures.
Preventive Dentistry acknowledges that:
a. dental disease is available.
b. oral health is attainable.
c. patients are entitled to have information and instruction that make them free of
the disease and to have permanent use of their natural teeth.
The role of the dentist in control of dental caries:
1- Elimination of active caries and restoring the damaged teeth to conserve their
function and aesthetic.
2- Provide necessary pulp and root canal treatment.
3- Provide dentures and bridges for the lost teeth.
4- Apply fissure sealants.
5- Carry epidemiological surveys for the incidence and caries increments.
The role of the dental auxiliary in control of dental caries:
1- Diet counselling which include:
a. record of family's dietary habits and daily routine that may affect food intake.
b. instructing mothers in elements of balanced diet and types of foods that are free of
sucrose.
c. prescribe diet for the family:
1- Based on family's habits, routine and income.
2- Substitution of non-cariogenic between meals foods for cariogenic
items.
3-immediately prescribed to mothers after birth in order to establish good habits rather
than to change bad habits later.
2-preventive auxiliary might apply fluoride and fissure sealants in some countries.
3- Provide dental health education in schools.
4- Provide dental health education to the community: a four point massage is agreed
to be delivered to the community:
a. avoid eating sweet, sticky foods between meals.
b. brush the teeth at least once a day with a fluoridated tooth paste.
c. support the fluoridation of water supplies.
d. visit the dentist for regular check-up.
The role of dentist in control of periodontal diseases:
1- Makes the patient aware of his state of gingival health and his need for change.
2- Recommendation of a control program.
3- Removal of calculus and polishing the teeth surfaces.
4- Carrying out conservative and orthodontic treatment when necessary to ensure
that no regions remain in the mouth whereby food can lodge and cause
gingivitis.
5- Carrying down epidemiological surveys to evaluate the state of periodontal
health in the community.
6- Performing surgical operations for gingiva like gingivectomy, widman flap.
The role of auxiliary in control of periodontal disease:
1- Conduct a control program of 4-5 visits.
2- Demonstration of plaque on the chair side using disclosing solution or
tablets.
3- Teaches the patient proper use of tooth brush.
4- Teaches the patient of proper use of floss and flossing technique.
5- Evaluate patient performance.
6- Emphasize on child to child teaching.
The dental auxiliary have a special role in dental health education program directed through
the individual or the community to control caries and periodontal
disease.
The community can be taught by means of group discussions, lectures, television,
newspapers, and posters. Special emphasize should be given to school children by giving
them education in oral and dental health
matters.
The establishment of a positive, friendly relationship and use of valid teaching techniques are
essential to success in a preventive program.
Lecture three
Numbering of teeth, deciduous and
permanent teeth
The primary dentitions are often referred to as the deciduous, baby or milk
teeth.
The most important function of these teeth is that they act as guides for the development of permanent
teeth. All the primary teeth should be in normal occlusion shortly after the age of two. The root should be
fully formed by the time the child is 3 years old.
Characteristics of primary teeth:
The primary teeth have certain characteristics that differentiate them from permanent
teeth:
1- The primary teeth are smaller than permanent teeth.
2-enamel is thinner and the pulp chamber is relatively large compared to that of permanent teeth.
3-the crowns are milk white in color compared to darker permanent teeth whose enamel is less
transparent.
4-roots of deciduous teeth are shorter, the root resorption of deciduous teeth starts one or two years before
the teeth are shed.
5-the crowns of deciduous are more bulbous than those of permanent teeth, cusps are more pointed and less
rounded, contact points involve a smaller surface of contact between teeth.
6-permeability of enamel of deciduous teeth remain the same till the commencement of root resorption
while that of permanent teeth is greatly reduced as the tooth become older in the mouth.
7-the deciduous teeth show a relatively greater degree of attrition compared to permanent
teeth.
The permanent dentition:
The permanent teeth replace the primary teeth, the molars are not replaced by the
permanent molar but the premolars erupt instead of them.
The incisors: are single – rooted teeth designed for cutting food without heavy
force.
Maxillary central incisors are the widest mesiodistally of any of the anterior
teeth.
The maxillary lateral incisors are smaller in all dimensions except in the root length,
and sometimes are congenitally missing.
The mandibular incisors show uniform development, they are smaller than any other
teeth.
The canines: the four canines are placed at the corners of the mouth. They are the largest
teeth in the mouth, and their single roots are longer than those of other
teeth.
The shape of the crowns promotes cleanliness and this preserve the canine and makes
them the last teeth to be lost.
The premolars eight in number, two in each quadrant, they lie posterior to the canines and
anterior to the first molars. The maxillary first premolar has two cusps, buccal and lingual
and two roots, buccal and
lingual.
The maxillary second premolar has two cusps, buccal and lingual and one
root.
The mandibular first premolar is always the smallest of the two mandibular
premolars.
Both mandibular premolars are single rooted, with the root of second premolar larger and
longer than that of first premolar.
The molars twelve in number, 3 in each quadrant.
The maxillary molars are the largest and shortest maxillary teeth. The maxillary first molar
the largest tooth in the arch, has four well developed cusps, mesio-buccal, mesio-lingual,
disto-buccal, disto-ligual and sometimes it has a fifth cusp found lingually. This tooth has
three roots, 2 buccal and one lingual.
Lecture four
Anatomy of tooth
Tooth structure:
Each tooth consists of a crown and one or more roots. The size and shape of the
crown and the size and number of roots are determined by functions of the tooth.
For example the upper first molar receives a very high pressure during mastication
compared to an incisor tooth, thus it have a bigger size and three roots compared to
the smaller size of the incisor crown which has a single
root.
The clinical crown: is that portion which is visible in the mouth.
The root: is that portion of the tooth normally embedded in the alveolar bone and
covered with cementum.
The root may be single as in anterior teeth or multiple with bifurcation or
trifurcation in the posterior molar and premolar teeth. The end of each root top is
known as the apex.
Cervix: is the line where the anatomic crown meets the root.
Cemento-enamel junction: is a line formed by the junction of the enamel of the
crown with the cementum of the root and is also called the cervical
line.
The enamel: is the hardest calcified tissue of the body. It is composed of crystals of
hydroxyl apatite arranged in prisms roughly perpendicular to the junction with the
underlying dentin. The closely packed crystals occupy 88% of the volume of the enamel,
the remaining 12% being water and organic material. By weight, enamel is 96% mineral.
Enamel is formed by ameloblasts during tooth development. Amelogenesis stops prior to
tooth eruption and no more enamel is produced. Enamel is relatively non-porous, and
smooth, therefore relatively easy to clean. Enamel has no sensory capacity and it protects
the underlying tissues from mechanical and chemical irritation.
The dentin: it form the main portion of the tooth (crown and root) it is about as hard as
bone but much softer than enamel. It is pale yellow in color, dentin is roughly 72%
minerals, 18% organic and 10% water by weight. Dentin is arranged as a collection of
tubules running from the pulp towards the enamel. Lining the inner aspect of the dentin
wall is a layer of cells known as odontoblasts.
Dentin is produced by the odontoblasts on the inside of the tooth throughout the life
of the tooth. Primary dentin is that dentin which is formed prior to tooth eruption.
Normal secondary dentin is formed continuously thereafter, causing a gradual
reduction in the size of the pulp chamber and is structurally similar to primary
dentin. Irregular secondary or tertiary dentin is formed in areas exposed to injury.
Dentin is a living tissue that can detect heat, cold, touch.
The endodontic system:
Consists of a pulp chamber (in the crown) and one or more pulp canals (within the
roots). The pulp chamber has pulp horns, which correspond to the shape of the
overlying tooth cusp. With time, the pulp chamber and canals become smaller as
secondary dentin is produced. The endodontic system contains the pulp.
The pulp: is a specialized connective tissue enclosed in a pulp chamber. It consists
mainly of fibroblasts and odontoblasts which line the walls of the pulp underneath
the dentin. It contains blood vessels and nerve fibers. The part of the pulp which lies
within the crown portion is called the coronal pulp, this include horns which are
projections of the pulp towards the cusps. The part of the pulp which is located
within the root is called the root pulp.
Cells of the pulp:
1- Odontoblasts form the dentin.
2- Fibroblasts or fibrocytes forms the ground substance.
3- Defence cells play an important role in the inflammatory reactions of the pulp.
The pulp contains unmyelinated fibers that control vasoconstriction in the pulp and
myelinated fibers that register pain via the trigeminal nerve. If pulp is exposed
through fracture or decay, it quickly becomes contaminated, inflamed and then
necrotic.
The cementum: a hard dental tissue covering the anatomical root of the tooth. It
begins at the cervical portion of the tooth at the cemento-enamel junction, and
continues to the apex in the root. The cementum at the root apex is cellular
(cementoblasts) and has some capacity for repair but the cementum near the crown is
acellular and has less regenerative capacity. Cementum is the tissue to which the
periodontal ligament fibers and gingiva attach. It is approximately 45% inorganic
material (mainly hydroxyl apatite), 33% organic material (mainly collagen) and 22%
water. The principle role of cementum is to serve as a medium by which the
periodontal ligaments can attach to the tooth for stability.
Physical characteristics:
1-hardness is less than dentin.
2-color is light yellowish. Darker than enamel and lighter in color than dentin.
3-it is permeable which decrease gradually by age.
Periodontal membrane:
Composed of bundles of white collagenous, connective tissue fibers which extend
from the cementum to the alveolar bone, it holds the tooth in place and transforms
the pressure on the crown to the root and alveolar bone during mastication.
The thickness of periodontal ligament varies in different individuals, in different
teeth and different locations in the same tooth.
Cells of periodontal ligament:
1-fibroblasts form periodontal fibers throughout life.
2-osteoblast for deposition of new bone.
3-osteoclasts for bone resorption.
4-defence cells similar to those occurring in pulp tissue.
Functions of periodontal ligament:
1- Formation of cementum, bone, periodontal tissues by fibroblast, and osteoblast
cells.
2- Supportive in the socket by the ligament against occlusal forces.
3- Sensory action.
4- Nutrition by blood vessels and lymph.
5- Resorption by osteoclast.
Lecture five
Dental caries, Definition,
Causes, Classification
Definition of Dental caries
Dental caries is defined as a progressive, irreversible, microbial disease affecting the
hard structures of the tooth exposed to the oral environment, resulting in
demineralization of the inorganic parts and dissolution of the organic constituents,
leading to a cavity formation.
The etiology of dental caries:
Dental caries is a multifactorial disease, all the following four factors are essential for
initiation of dental caries:
1-Microorganisms mainly Streptococcus mutans, these bacteria are characterized by
their ability to ferment sucrose to produce extracellular polysaccharide.
2- Carbohydrates.
3- Tooth.
4-Time required for acid production and for demineralization of tooth.
Teeth
There are certain diseases and disorders affecting teeth which may leave an individual
at a greater risk for caries. Amelogenesis imperfecta, is a disease in which the enamel
does not fully form or forms in insufficient amounts. In both cases, teeth may be left
more vulnerable to decay because the enamel is not able to protect the tooth.
The anatomy of teeth may affect the likelihood of caries formation. Where the deep
grooves of teeth are more susceptible to dental caries. Also, caries are more likely to
develop when food is trapped between teeth.
Bacteria
The mouth contains a wide variety of oral bacteria, but only a few specific species of
bacteria are believed to cause dental caries: specially streptococcus mutans and
Lactobacilli among them, but streptococcus mutans are the most predominant
bacteria causing dental caries. Bacteria collect around the teeth and gums in a sticky,
creamy-coloured mass called plaque, which serves as a biofilm. Some sites collect
plaque more commonly than others. The grooves on the biting surfaces of molar and
premolar teeth provide microscopic retention, as does the point of contact between
teeth.
Fermentable carbohydrates
Bacteria in a person's mouth convert glucose, fructose, and most commonly
sucrose into acids such as lactic acid through a glycolytic process called
fermentation. If left in contact with the tooth, these acids may cause
demineralization, which is the dissolution of its mineral content. The kinetics of
the acid production was shown by Stephan curve (1944) where he found a rapid
drop in the pH of the mouth to 5 or less lasting for 40-60 minutes.
The mineral content of teeth is sensitive to increases in acidity from the
production of acid.
The process is dynamic, however, as remineralization can also occur if the acid
is neutralized by saliva or mouthwash. Fluoride toothpaste or dental varnish
may aid remineralization. If demineralization continues over time, enough
mineral content may be lost so that the soft organic material left behind
disintegrates, forming a cavity or hole.
Time
The frequency of which teeth are exposed to cariogenic (acidic) environments
affects the likelihood of caries development. Since teeth are vulnerable during
these acidic periods, the development of dental caries relies heavily on the
frequency of acid exposure.
The carious process can begin within months of a tooth erupting into the mouth
if the diet is sufficiently rich in suitable carbohydrates and oral hygiene is very
poor. This can occur, for example, when children continuously drink sugary
drinks from baby bottles.
Pathophysiology of enamel
caries:
Enamel is a highly mineralized acellular tissue, and caries act upon it
through a chemical process brought on by the acidic environment produced
by bacteria. As the bacteria consume the sugar and use it for their own
energy, they produce lactic acid. The effects of this process include the
demineralization of crystals in the enamel, caused by acids, over time until
the bacteria physically penetrate the dentin. Enamel rods, which are the
basic unit of the enamel structure, run perpendicularly from the surface of
the tooth to the dentin.
Since demineralization of enamel by caries generally follows the direction of
the enamel rods, the different triangular patterns between pit and fissure and
smooth-surface caries develop in the enamel because the orientation of enamel
rods are different in the two areas of the tooth . As the enamel loses minerals,
and dental caries progress, they develop several distinct zones, visible under a
light microscope. From the deepest layer of the enamel to the enamel surface,
the identified areas are the: translucent zone, dark zones, body of the lesion,
and surface zone. The translucent zone is the first visible sign of caries and
coincides with a 1-2% loss of minerals. A slight remineralization of enamel
occurs in the dark zone, which serves as an example of how the development of
dental caries is an active process with alternating changes. The area of greatest
demineralization and destruction is in the body of the lesion itself. The surface
zone remains relatively mineralized and is present until the loss of tooth
structure results in cavitation.
Lecture six
Caries of dentin and cementum, types
of dental caries, diseases of the dental
pulp
Caries of Dentin
Unlike enamel, the dentin reacts to the progression of dental caries. After tooth
formation, the ameloblasts, which produce enamel, are destroyed once enamel
formation is complete and thus cannot later regenerate enamel after its destruction. On
the other hand, dentin is produced continuously throughout life by odontoblasts, which
reside at the border between the pulp and dentin. Since odontoblasts are present, a
stimulus, such as caries, can trigger a biologic response. These defense mechanisms
include the formation of sclerotic and tertiary dentin.
In dentin from the deepest layer to the enamel, the distinct areas affected by caries are
the translucent zone, the zone of bacterial penetration, and the zone of destruction. The
translucent zone represents the advancing front of the carious process and is where the
initial demineralization begins. The zones of bacterial penetration and destruction are
the locations of invading bacteria and ultimately the decomposition of dentin.
Sclerotic dentin
The structure of dentin is an arrangement of microscopic channels, called dentinal
tubules, which radiate outward from the pulp chamber to the exterior cementum or
enamel border. The diameter of the dentinal tubules is largest near the pulp (about
2.5 μm) and smallest (about 900 nm) at the junction of dentin and enamel. The carious
process continues through the dentinal tubules, which are responsible for the triangular
patterns resulting from the progression of caries deep into the tooth. The tubules also
allow caries to progress faster.
In response, the fluid inside the tubules brings immunoglobulins from the immune
system to fight the bacterial infection. At the same time, there is an increase of
mineralization of the surrounding tubules.
This results in a constriction of the tubules, which is an attempt to slow the bacterial
progression. In addition, as the acid from the bacteria demineralizes the hydroxyapatite
crystals, calcium and phosphorus are released, allowing for the precipitation of more
crystals which fall deeper into the dentinal tubule. These crystals form a barrier and
slow the advancement of caries. After these protective responses, the dentin is
considered sclerotic.
Fluids within dentinal tubules are believed to be the mechanism by which pain receptors
are triggered within the pulp of the tooth. Since sclerotic dentin prevents the passage of
such fluids, pain that would otherwise serve as a warning of the invading bacteria may
not develop at first. Consequently, dental caries may progress for a long period of time
without any sensitivity of the tooth, allowing for greater loss of tooth structure.
Tertiary dentin
In response to dental caries, there may the production of more dentin toward the
direction of the pulp. This new dentin is referred to as tertiary dentin. Tertiary dentin is
produced to protect the pulp for as long as possible from the advancing bacteria. As
more tertiary dentin is produced, the size of the pulp decreases. This type of dentin has
been subdivided according to the presence or absence of the original odontoblasts. If
the odontoblasts survive long enough to react to the dental caries, then the dentin
produced is called "reactionary" dentin. If the odontoblasts are killed, the dentin
produced is called "reparative" dentin.
Reparative dentin is produced at an average of 1.5 μm/day, the resulting dentin
contains irregularly-shaped dentinal tubules which may not line up with existing
dentinal tubules. This diminishes the ability for dental caries to progress within the
dentinal tubules.
Caries in cementum (root caries):
It increases with age due to the increased exposure of cementum. So people with
periodontal disease can show high incidence of cementum caries which show a dark
brown or deep yellowish color.
Types of dental caries:
1- Primary caries: - caries occurs for the first time on the tooth surface.
2- Secondary caries: - when caries occurring at the margins and below an old restoration
mainly due to fracture of filling.
3- Acute caries: - rapidly progressing caries resulting in acute pain and early
involvement of pulp.
4- Chronic caries: - slowly progressing caries which is asymptomatic until pulp
involvement.
5- Rampant caries: - is a suddenly appearing, rapidly type of caries resulting in early
pulp involvement.
6- Arrested caries: - is that caries in which after initiation, carious lesions do not
progress further and a calcified mass mostly yellow, brown or blackish in color is
formed at the cavity floor.
7- Pit and fissure sealant caries: - it is the caries which start from pit or fissure on the
tooth surface.
8- Smooth surface caries: - initiates from smooth surface and not from any pit or
fissure.
9- Occlusal caries: - starts from occlusal surface of teeth.
10-cervical caries: - starting from the cervical margin on the tooth surface.
Diseases of the dental pulp:
Hyperemia: is an increase of blood in the small arteries of the pulp. These changes
causes pressure on the nerve fibers in the pulp causing pain, if these causes are
removed, the condition become normal.
Pulpitis: when bacteria in a carious lesion reach the pulp and inflammation takes place
toothache result and should be diagnosed by the dentist.
Pulp polyp: in young children pulp, sometimes hyperplastic tissue grows out from the
cavity.
Periapical abscess: when the pulp become generally inflamed pus reach the pulp canal
and pass out through the root to the apex end where it penetrate the bone passing
under the soft tissues of the jaw. Sometimes the jaw swell when the pus cannot find a
pathway for drainage but sometimes pus find a way to drain into the mouth in a
fistula.
Lecture seven
Gingivitis, periodontitis (role of calculus
and dental plaque)
The periodontium:
It is the supporting structure of a tooth, helping to attach the tooth to surrounding tissues.
It consists of 1- cementum, 2- periodontal ligaments, 3- alveolar bone, 4- gingiva.
Periodontal ligaments connect the alveolar bone to the cementum.
Alveolar bone surrounds the roots of teeth to provide support and creates what is called
alveolus or socket. The lining over the bone is the gingiva or gum, which is visible in the
mouth.
Gingiva is the mucosal tissue that overlay the jaws. There are three different types of
epithelium associated with the gingiva:Gingival, junctional, and sulcular epithelium.
Types of gingiva:
1- Marginal gingiva, 2- attached gingiva, 3- interdental gingiva.
Marginal gingiva (free gingiva): is the terminal edge or border of the gingiva surrounding
the tooth in collar like fashion. It forms the soft tissue wall of the gingival sulcus.
The gingival sulcus: is the shallow space around the tooth bounded by the surface of
the tooth on one side, free margin of the gingiva on other side. It is V- shaped and
normally about 1-1.5 mm in depth when it becomes more than 3 mm it becomes
pathological pocket.
The attached gingiva: it is firm and tightly bounded to the underlying periosteum of
the alveolar bone. It extends apically to the alveolar mucosa, which is loose,
movable and red in color while the marginal and attached gingiva are pink in color.
The inter-dental gingiva: it usually consists of two papillae, one labial and one
lingual or (palatal), and the tissue between them, which cross the bucco- lingual
distance below the contact area.
Characteristic of healthy gingiva:
1-Color: pink, sometime contain melanin pigmentation.
2- Consistency: resilient.
3- Contour: end knife –edge around tooth.
4- Gingival sulcus depth: 1-1.5 mm.
5-Gingival sulcus contain gingival fluid which is exudates from blood plasma.
Gingivitis definition and types
Gingivitis: is an infection that is an early sign of gum disease. It occurs
when plaque builds up between the teeth and gums.
Characteristic of inflamed gingiva:1. color: red.
2-Consistency: edematous.
3-Gingival sulcus depth above 3mm in depth and may be filled with
calculus.
4- Contour: can be moved by probe.
Types of gingivitis:
1- According to course and duration:
a- acute gingivitis: is of sudden onset and short duration and can be
painful.
b- Recurrent gingivitis: reappears after having been eliminated by the
treatment or disappearing spontaneously.
c- Chronic gingivitis: is slow in onset and of long duration, it is painless and
the type most commonly
encountered.
2- According to the distribution:
a- Localized gingivitis: is confined to the gingiva of a single tooth or group of
teeth.
b- Generalized gingivitis: it involve the entire mouth.
c- Marginal gingivitis: involve the gingival margin and may include the
attached gingiva.
d- Papillary gingivitis: involve the inter-dental papillae and extends into the
adjacent portion of the gingival margin.
e- Diffuse gingivitis: affects the gingival margin, the attached gingiva and the
inter-dental papillae.
Self test (1)
Enumerate types of gingivitis
check your answers in the key answer page at the end of module
Periodontitis definition and types
Periodontitis: untreated gingivitis can advance to periodontitis. With time
plaque can spread and grow below the gum line, toxins produced by bacteria
in plaque irritate the gums, the toxins stimulate a chronic inflammatory
response and the tissues and the bone that support the teeth are broken.
Gum will separated from the teeth, forming pockets that become infected. As
the disease progress, the pockets deepen and more gum tissue and bone are
destroyed, eventually, teeth can become loose and may have to be removed.
Types of periodontitis:
There are many forms of periodontitis:
1-Aggressive periodontitis: common features include rapid attachment loss
and bone destruction.
2-Chronic periodontitis: this is most frequently occurring form of periodontitis
and is characterized by pocket formation or recession of the gingiva,
progression of attachment loss occurs slowly.
3-Periodontitis as a manifestation of systemic disease: begins at a young
age, systemic conditions such as heart disease, respiratory disease and
diabetic are associated with this form of periodontitis.
4-Necrotizing periodontal disease: is an infection characterized by necrosis
of gingival tissues, periodontal ligament and alveolar bone. These lesions are
most commonly observed in individuals with systemic conditions such as HIV
infection, malnutrition and immuno-suppression.
Self test (2)
What are the types of periodontitis?
-check your answers in the key answer page at the end of module
Periodontal pocket definition and types
Periodontal pocket is a pathological deepening of gingival sulcus.
Types of periodontal pocket
It is of two types:
1- False pocket: formed by gingival enlargement without destruction of the
underlying periodontal tissue.
2-True pocket: this occurs with destruction of the supporting periodontal
tissue. It is classified into:
a- Supra bony pocket: when the bottom of the pocket is coronal to the
underlying alveolar bone.
b- Infra bony pocket: when the bottom of the pocket is apical to the level of
the adjacent alveolar bone.
Lecture 8
Dental stain, definition and types
Definition of dental stain
These are pigments deposited on the tooth surface, they are produced by the chromogenic
bacteria by the action on foods.
Types of dental stains:
We have 1. Extrinsic stain formed on the tooth surface enamel.
2. Intrinsic formed inside the inner layers and underneath it in dentin and pulp areas.
Intrinsic tooth discoloration
The formation of intrinsically discoloured teeth occurs during tooth development results in
an alteration of the light transmitting properties of the tooth structure. A number of metabolic
diseases and systemic factors are known to affect the developing dentition and cause
discoloration as a consequence.
Causes of intrinsic stain:
Amelogenesis imperfecta
Dentinogenesis imperfecta
Tetracycline staining
Fluorosis
Enamel hypoplasia
Pulpal haemorrhagic products
Ageing
1-Amelogenesis imperfecta: In this hereditary condition, enamel formation is disturbed
with regard to mineralization or matrix formation. The appearance varying from the
relatively mild hypomature 'snow-capped' enamel to the more severe hereditary
hypoplasia with thin, hard enamel which has a yellow to yellow-brown appearance.
Amelogenesis Imperfecta
2-Dentinogenesis imperfecta: Dentine defects may occur genetically or through
environmental influences. Both dentitions are affected, the primary dentition usually
more severely so. The teeth are usually bluish or brown in color, the dentin undergoes
rapid wear. Once the dentin is exposed, teeth rapidly show brown discoloration, by
absorption of chromogens into the porous dentin.
Dentinogenesis imperfecta
3-Tetracycline staining: Systemic administration of tetracycline during development
is associated with deposition of tetracycline within bone and the dental hard tissues.
Dentine has been shown to be more heavily stained than enamel. Tetracycline is
able to cross the placental barrier and should be avoided from 29 weeks in utero
until full term to prevent incorporation into the dental tissues. Since the permanent
teeth continue to develop in the infant and young child until 12 years of age,
tetracycline administration should be avoided in children below this age and in
breast-feeding and expectant mothers. The color changes involved depend upon the
precise medication used, the dosage and the period of time over which the
medication was given. Teeth affected by tetracycline have a yellowish or browngrey appearance which is worse on eruption and diminishes with time. Exposure to
light changes the color to brown, the anterior teeth are particularly susceptible to
light induced color changes.
Tetracycline staining
4-Fluorosis: This may arise from naturally occurring water supplies or from
fluoride delivered in mouthrinses, tablets or toothpastes as a supplement. The
severity is related to age and dose, with the primary and secondary dentitions both
being affected. The enamel is often affected and may vary from areas of flecking to
diffuse opacious mottling, whilst the color of the enamel ranges from chalky white
to a dark brown/black appearance. The brown/black discoloration is post-eruptive
and probably caused by the internalization of extrinsic stain into the porous enamel.
Dental fluorosis
5-Enamel hypoplasia: This condition may be localized or generalized. The most
common localized cause of enamel hypoplasia is likely to occur following trauma or
infection in the primary dentition. Such localized damage to the tooth-germ will
often produce a hypoplastic enamel defect, which can be related chronologically to
the injury. Disturbance of the developing tooth germ may occur in a large number of
fetal or maternal conditions eg maternal vitamin D deficiency, rubella infection, drug
intake during pregnancy. The effect is directly related to the degree of systemic
upset. There may be pitting or grooving which predisposes to extrinsic staining of
the enamel in the region of tooth disturbed, often then becoming internalized.
Localised enamel hypoplasia on both upper central incisors
6-Pulpal haemorrhagic products: The discoloration of teeth following severe trauma
was considered to be caused by pulpal haemorrhage. Haemolysis of the red blood cells
would follow and release the haem group to combine with the putrefying pulpal tissue
to give the tooth a darkened appearance.
Haemorrhagic products in a non-vital central
7-Ageing: The natural laying down of secondary dentine affects the lighttransmitting properties of teeth resulting in a gradual darkening of teeth with
age.
Types of extrinsic stain:
Causes of extrinsic stain are coffee, tea, oranges and tobacco
The most common stains are:1- Tobacco stains:- these are dark brown or black stains deposited on the tooth
surfaces, pits and fissures of smokers and tobacco chewers. They are removed with
difficulty.
2- Brown stains:- these are thin translucent, its due to poor oral hygiene.
3- green stains:- are seen in children with poor oral hygiene, more in boys than in
girls, its due to fluorescent bacteria and fungi like penicillin and
Aspergillus.
4-black stains: - these are firmly attached and are seen in deciduous teeth with poor
oral hygiene.
Lecture 9
Prevention of dental caries
Levels of prevention:
1- Primary prevention.
2- Secondary prevention.
3- Tertiary prevention.
Primary prevention: directed toward the prepathogenesis stage of the disease to prevent
the initiation of disease like plaque removal, brushing and flossing, fissure
sealant.
2- Secondary prevention: These are the steps to prevent the progression and recurrence
of the initial stages of the disease ex. Early treatment of chronic marginal gingivitis, to
prevent the progress into severe
periodontitis.
3- Tertiary prevention: In this type, efforts are made to prevent the loss of function that
may happen as a result of the disease and to restore the lost function, form and esthetics
ex. Prosthodontic appliances and
implants.
Types of primary preventive measures provided by the community:1- Community water fluoridation.
2- School water fluoridation.
3- Fluoride mouth rinse programs.
4- Oral and dental health education programs.
5- Fluoride supplements programs.
6- Salt fluoridation.
7- Milk fluoridation.
Types of primary preventive measures provided by the dental professionals:1- Professional topical fluoride application.
2- Pit and fissure sealants.
3- Dietary habit counseling.
4- Plaque control program.
Types of primary preventive measures observed by the individuals:1- Fluoride dentifrices and mouthwashes.
2- Self applied topical fluoride products.
3- Oral hygiene practices.
Primary preventive measures taken by the community (systemic
benefit):
1- Fluoridation of water supply:
Water fluoridation means the upward adjustment of the level of fluoride
content of drinking water supply to an optimal level to prevent caries and not
cause dental fluorosis. It is about 1 ppm (part per million).
However, the optimum fluoride levels vary with the weather, in warm and dry
whether, the average consumption of water increases. In cold whether the
amount of water consumption decreases. The optimum fluoride level in very
cold countries may be as high as 1.2 ppm (part per million) and in very hot and
dry countries it may be as low as 0.5 ppm.
The advantages of communal water fluoridation:1- Most effective method for prevention of dental caries.
2- Economic method.
3- Practical method.
4- Reduction of dental caries from 50% to 65%.
2- School water fluoridation:High level of fluoride is used in this method which is about 4 ppm, because
children remain in school only 4 to 5 hours a day.
The disadvantages of this method:
1- By the age 6 years (school going age) all the teeth except third molars are in the
advanced stage of mineralization so pre-eruptive benefit of fluoride is very much
reduced.
2- There is interruption in this regimen (as in holidays and weekends).
The advantages of school water fluoridation:
1- Low cost.
2- No effort is needed by the child.
3- Caries reduction up to 40%.
3- Fluoride supplements programs:
Fluoride supplementation should be undertaken when it is impossible to adjust
drinking water fluoride to optimum levels.
Types of fluoride supplements:
1- Tablets.
2- Lozenges.
3- Drops and fluoride vitamin.
These work both systemically and topically.
4- Salt fluoridation:
It is also effective method to deliver fluoride to the population where water
fluoridation is not possible. This method is safe and cheap method.
5- Milk fluoridation:
It is effective method in reducing dental caries but it is costly and some
people dislike milk.
Self test (2)
What are the disadvantages of milk fluoridation?
-Check your answers in the key answer page at the end of module.
6- Fluoride mouth rinse programs:
Rinsing the mouth with fluoride solutions (sodium fluoride solution mostly
used), it is a very effective topical method of caries control which reduces
caries about 30%, mostly two concentrations of sodium fluoride solutions are
used.
7- Oral and dental health programs:
Through the educational programs in schools and through mass media like
tv, radio and in, it is important to explain to individuals how they can prevent
dental caries by:
1- Brushing teeth with dentifrices.
2- Diet and sugar restrictions.
3- Water fluoride is benefit.
4- Visit dentist regularly.
Primary preventive services provided by the dental profession:
1- Professional topical fluoride application:Topical fluoride therapy means the local application of relatively high
concentrations of fluoride to all erupted surfaces of teeth to prevent dental
caries.
Topical fluoride includes mouthwashes, solutions, gels, varnishes, and
paste.
The solutions commonly used are:
1- Sodium fluoride (2%).
2- Stannous fluoride (8%).
3- Acidulated phosphate fluoride (1.23%).
Method of preparation of 2% of sodium fluoride solution:
Twenty gram of sodium fluoride powder is dissolved in one litre of distilled
water in a plastic bottle.
Method of application of stannous fluoride solution:Before application, content of one capsule is dissolved in 100 ml of distilled
water in a small plastic bottle, and then the solution is applied on the isolated
tooth surfaces.
Note: - polishing with pumice of all the surfaces of all the teeth should
be done before application any topical fluoride, isolation of teeth with
cotton rolls and dried with air. The solution of topical fluoride should be
applied for 4 minutes.
Method of application of acidulated phosphate
fluoride:
After prophylaxis, teeth are isolated with cotton rolls. The teeth then
dried and gel is applied with piece of cotton on a tweezer or it can be
applied with disposable tray, the gel is kept on teeth for 4
minutes.
Fluoride varnishes:1- These are very useful to use in young children.
2- It remains in contact with the tooth for a longer period than the
solutions and gels.
3- The method of application is like solutions and gels.
Prophylactic paste:After proper oral prophylaxis, the polishing is done with this paste
before application of topical fluorides, these paste may contain
sodium fluoride, or stannous fluoride or acidulated phosphate
fluoride. The surface enamel contains higher levels of fluoride than
is found in internal layers, therefore, a prophylaxis removes a
fluoride- rich layer. So if prophylaxis pastes containing fluoride are
used, the lost fluoride is replenished.
Primary preventive measures observed by the individual (Self
applied topical fluoride
products):
1-Dentifrices:
A dentifrice or tooth paste is a substance used with a tooth brush for
the purpose of cleaning the accessible surfaces of the teeth.
The functions of tooth paste are:1- Tooth brushing.
2- Anticaries action.
3- Minimizing plaque build up.
4- Removal of stain.
5- Mouth freshener.
2- Fluoride mouth washes:
Indications:
1- Persons having high dental caries and living in fluoride deficient area can
be advised to use a fluoride mouth rinses once or twice a day at home
specially at bed time.
2- Patients with decreased salivary flow whose teeth are highly susceptible
to dental caries.
3- For orthodontic patients.
Mouth rinses usually contain 0.05% neutral sodium fluoride solutions.
Caries reduction about 25- 30%.
Not advised for preschool children, because they might swallow it.
3- Fluoride gel:
These are home use gels contain stannous fluoride and neutral or acidulated
sodium fluoride. These are applied by disposable trays by persons themselves
at home.
Lecture 10
Pit and fissure sealant
Definition of fissure sealants : pit and fissure sealants these are materials
which are firmly attach to the enamel surface and isolate the pit and fissure
from bacteria present in the mouth so caries will be
prevented.
Why sealants?
Topical application of fluorides are very effective in reducing caries on the
smooth surfaces, they are not very effective in reducing caries that occur in
pit and fissure because topical fluorides cannot enter deep pit and fissures.
Therefore, to prevent caries in these areas fissure sealants have been
developd.
Indications for fissure sealants:
1- For individuals with a moderate or high risk of dental caries.
2- Individuals have incipient caries.
3-Individuals have pits and fissures that are anatomically susceptible to
caries.
First and second molars are at equal risk and have a higher probability of
decay than any other tooth type. Consequently, both first and second molars
are the main candidates for sealants. Premolars are much less susceptible to
decay than molars and are less likely to be candidates for sealant. Sealants
should be placed as early as possible after the occlusal surface is free of
gingival tissue and up to 4 years after eruption.
Placement may be indicated beyond 4 years post-eruption depending upon
the caries susceptibility of the individual.
Contraindications for Sealants
1- Posterior teeth that have shallow and/or low caries risk are poor candidates
for sealant placement.
2- Sealants are contraindicated for teeth with proximal decay
3- Teeth with obvious occlusal decay.
Materials used as a fissure sealant:
Several materials were used:
1- Chemical treatment of enamel with silver nitrate.
2- Prophylactic odontology (restoration of the fissure with amalgam).
3- Sealing of the fissure: several materials have been tried like glass ionomer
cement. The most common type material use as fissure sealant is a
composite resin without filler.
Fissure sealants materials either self-cured (autopolymerized or chemical
cured) or light cured.
Autopolymerizing sealants have high long-term retention rates, with 60% of
surfaces remaining covered after 5 to 7 years.
Visible light curing sealants have retention rates similar to autopolymerizing
sealants.
Fluoride-containing visible light cured sealants have only been evaluated
in short-term studies but have retention rates similar to autopolymerizing
and conventional light cured sealants for the equivalent follow-up
periods. Whether or not the incorporation of fluoride leads to further
reductions in caries has not been determined.
Retention rates for glass ionomer cements, both conventional and resinreinforced, are significantly lower than that of resin based sealants and
their use is not recommended.
Technique for application of fissure sealant.
1- Prophylaxis is done. Before sealant placement, the tooth surface must be
cleaned of plaque and other debris. Surfaces can be cleaned using a
prophylactic cup or brush with or without pumice, with an explorer and forceful
rinsing with water, with a toothbrush and toothpaste. Where different cleaning
methods have been compared, no differences in retention rates have been
found.
2- Isolate and dry the tooth.
Complete isolation of the tooth from contamination by saliva is the most
important aspect of sealant placement. Isolation by rubber dam or cotton rolls
are equally effective and result in similar retention rates.
3- Etching for 15 second with 20-50% phosphoric acid.
In order for the sealant to adhere the enamel surface needs to be etched,
usually with an orthophosphoric acid liquid gel. Liquid and gel are equally
effective in terms of surface penetration and sealant retention. Clinical studies
indicate that a 15 second etch is adequate for sealant retention and no
additional benefit received from longer etching times of 45 or 60 seconds.
4- Wash thoroughly, re-isolate and dry very well.
Rinsing and drying times are not important as long as they are sufficient to
ensure the complete removal of all etching material from the tooth surface.
5- Apply fissure sealant (polymerization depend whether the material is selfcured or light cure).
All pits and fissures should be sealed. The placing of a bonding agent on the
surface prior to the sealant does not appear to enhance retention rates.
In order to reduce contamination, it is generally recommended that the
polymerization of light cured sealants is undertaken immediately after
placement. However, one study suggested that allowing the sealant to sit on
the tooth surface for 20 seconds prior to polymerization increased sealant
penetration.
6- Evaluation of the sealant:
The sealant should be inspected to ensure complete coverage of the occlusal
surface and the occlusion checked for interferences. Filled sealants tend to
be thicker than unfilled sealants and are more likely to require adjustment
after placement.
Self test (1)
Enumerate the steps for fissure sealant application.
Check your answers in the key answer page at the end of module.
Lecture 11
Diet, nutrition counseling for
prevention of dental caries
Definition of nutrition and nutrients
Nutrition: is the combination of process by which consumed food is used for
structural and functional process of every cell of the body.
Nutrients: are the chemical constituents of foods like protein, carbohydrates,
fats, vitamins, minerals (calcium, iron, zinc, fluoride).
Systemic nutritional influences:
Protein deficiency cause delay eruption of deciduous teeth, teeth erupted are
smaller in size and more caries prone.
Vitamins:
Vitamin A deficiency causes hyperplasia of gingival tissue, hypoplastic and
chalky white incisors, atrophy of salivary glands resulting in increase in dental
caries.
Vitamin D deficiency causes hypoplasia of enamel and dentin.
Vitamin E deficiency cause white chalky teeth.
Minerals:
Calcium and phosphorus: deficiency cause altered calcification, increased
dental caries.
Zinc deficiency cause delayed wound healing.
Self test (1) write (T) for true sentences and (F) for the false one.
1-calcium deficiency cause altered calcification.
2-Vitamin D deficiency cause hypoplasia of enamel and dentin
3-Vitamin E deficiency cause white chalky teeth.
Check your answers in the key answer page at the end of module.
Diet (sugars) and dental caries (post eruptive effect):
There is a wealth of evidence to show the role of dietary sugars in the etiology of
dental caries. The evidence comes from many different types of studies including
human and animal studies, information from these studies revealed that sugars are
the main reason for getting tooth decay. Eating sugar in small quantities and only
two to three times a day will limit the harm caused to the teeth, but if a lot of sugar
is consumed over the day, dental caries is very likely to
develop.
Classification of sugars for health purposes.
Are some sugars more cariogenic than others?
1-Sucrose, glucose, fructose and maltose have similar cariogenicity.
2- Lactose is less cariogenicity.
3- Intrinsic sugars are not thought to be harmful to teeth.
4- Milk sugars, when naturally present in milk or milk products, are not harmful
to teeth.
5- Non- milk extrinsic sugars are sugars that are harmful to teeth.
Milk and dental caries:
1- The sugar in milk is lactose, which is less cariogenic.
2- Milk contain calcium, phosphorus which protect against demineralization.
3-Human breast milk is higher in lactose and lower in phosphorus and
calcium, however, normal breast feeding does not cause dental caries.
Other foods and dental caries:
1- Studies showed that cheese is anticariogenic, consumption of cheese
following a sugar snack stimulate salivary secretion and increases calcium
concentration which can influence the balance between de and remineralization of enamel.
2- Foods that are good stimuli to salivary flow protect against dental caries
examples sugar free chewing gum, peanut and cheese.
1-Recommendation for prevention of dental caries (dietary caries
control):
Restrict the number of eating times to three main meals, avoid sugar in between
meals (take low carbohydrate and high protein in between
meals).
2- Increase eating protein foods like meat, fish, milk and eggs.
3- Eliminate eating sticky sweets like chocolates, toffees, candies and
cakes.
4- Eating raw vegetables and fruits this will reduce dental plaque formation and
increase salivary flow rate.
Means of controlling the oral microflora (vaccination)
It is well known by now, that there are different research teams around the world
trying to find a vaccine for dental caries. Several problems are facing these
researchers and these lie in the fact that in spite of the attempts by vaccination
supporters to put the whole or the major responsibility of the carious process on
streptococcus mutans still other bacteria are related to dental caries like
Lactobacillus. On the other hand it was found that streptococcus mutans is further
subdivided into a least 6 distinct species each of which is specific for initiating
caries on certain surface of the tooth while the others are not. Also these species
differ from each other in terms of physiology and functions important in plaque
formation. So developing a vaccine for all these bacteria with their sub- groups is
still not possible at the present time.
Lecture 12
Prevention and treatment of
gingivitis and periodontitis
The principle cause of periodontal disease is dental plaque which is
responsible for forming the first stage of calculus.
Definition of dental plaque: Dental plaque is the non- mineralized, bacterial
aggregation on teeth and other solid structures in the mouth which cannot be
removed by rinsing but can be removed by brushing and
flossing.
Definition and types of dental calculus:A last stage in the maturation of some dental plaques is characterized by the
appearance of mineralization in the deeper areas of the plaque to form dental
calculus. Calculus is not in itself harmful. The major reason to prevent or
remove calculus because it is always covered by a layer of unmineralized,
viable bacteria associated with the external calculus surface. Calculus cannot
be removed by personal oral hygiene techniques, such as brushing or
flossing.
In addition to local factors contributing to calculus formation, behavioral and
systemic conditions appear to facilitate calculus formation. For example,
smoking causes an accelerated formation of calculus, children with asthma
form calculus twice the rate as other children.
Types of dental calculus
1- Supragingival calculus: forms on the tooth coronal to the margin of the
gingival tissues and develop opposite the duct orifices of the major salivary
glands, such as on the facial surfaces of the maxillary molars and on the
lingual surfaces of the mandibular incisors, and it can form in the fissures of
teeth.
2- Subgingival calculus: forms from calcium, phosphate, and organic
materials derived from serum usually found within the gingival sulcus.
Subgingival calculus is harder than supragingival one and more closely attach
to the tooth, therefore it is more difficult to remove than supragingival calculus.
The supragingival calculus appears as a yellow- to white mass, where as the
subgingival calculus appears gray to black.
Prevention of periodontal diseases:
By proper brushing and flossing, plaque could be affectively removed by the
patient.
Plaque takes about 24 hours to reform, therefore, if plaque is completely
removed at least once every 24 hours the prevention of gingivitis is possible for
most individuals.
Tooth brushing:
Teeth should be brushes immediately after each meal, especially after the last
food of the day. But it is widely accepted that brushing two times daily effectively
is enough to maintain good oral hygiene for the gingiva. The brushing technique
should be used systematically, first in the maxilla and then in the mandible. One
begins on the buccal aspects of the molars and then works round, via anterior
teeth, to the molars on the other side. The process is then repeated for the
lingual surfaces, finally the occlusal surfaces are scrubbed by moving the brush
back and forth.
Each area should be brushed at least 10 times, ensuring maximum cleanliness
of the teeth and maximum stimulation of the gingival tissues. For most purposes
a medium or hard bristle or nylon brush may be used.
Flossing :
Silk floss is wrapped around two fingers and gently pulled backwards and
forwards between the teeth, taking care to avoid damage to the
gingiva.
Detection of plaque:
1- Direct vision: thin plaque may be translucent and not visible, stained plaque by
tobacco for example is visible. Thick plaque can be seen with necked eye.
2- Use of explorer: plaque may feel rough as it starts to form but later on it is
slippery.
3-Disclosing tablets:
Purpose of using the tablets
1- For personalized patient instruction in the location of soft deposits and the
techniques for removal.
2- Self evaluation by the patient on a daily basis during initial instructions and
periodic check after.
3- Continuing evaluation by the dental hygienist of the effectiveness of the
instruction for the patient.
Method of use:
They are applied in solution, the application may be made to each quadrant of
teeth in this way:
a. dry teeth with compressed air.
b. use very small cotton pellets to carry the solution to teeth.
c. apply solution to crowns of teeth only.
d. remove excess of solution.
e. polish disclosed areas as required to remove visible deposits.
The effect: clean tooth surfaces do not absorb the coloring agent, when pellicle
and dental plaque are present, they absorb the agent and are disclosed.
Pellicle stains thin, where as plaque appear darker and thicker.
Curative treatment of periodontal disease:
1- Scaling and polishing: scaling is the procedure of calculus removal from the
surfaces of the teeth using either hand instruments or cavitron ultrasonic
scaler. Polishing can be done using a rubber cup or soft brush on a low speed
hand piece.
2- Root planning: is the process by which the surfaces of the roots are made
smooth by the removal of residual fine calculus and necrotic
cementum.
3- Elimination of other causes of gingivitis: badly placed fillings, faulty dentures
and orthodontic appliances, caries …..etc.
In chronic periodontitis treatment is directed to prevent further destruction of the
periodontium, this is achieved by:
1- Removal of supra and sub gingival calculus and plaque by scaling and polishing.
2- Elimination of stagnation areas due to poor fillings, dentures.
3- Removal of pockets by gingivectomy.
4- Instruction of patient on careful brushing of teeth and gum and use of wood
points to cleanse and stimulate the inter-dental areas.
Gingivectomy: removal of gingival tissue to eliminate pocket from around the
teeth.
Lecture 13
Brushing
techniques
Classification of tooth brushing methods:
These methods can be classified into six types:
1- The roll or rolling stroke method.
2- Vibratory technique.
3- Circular techniques.
4- Vertical technique.
5- Horizontal technique.
6- Physiological technique.
1- The roll or rolling stroke method:
Indications:
1- Children and adult patients with limited dexterity.
2- Patients requiring gingival massage and stimulation.
3- Cleaning gingiva and removal of plaque, and food debris from the teeth
without emphasis on gingival sulcus.
Technique:
In this method, the bristles are placed at 45º angle above the free gingiva with
the bristles pointed toward the apices. Exerting light pressure, draw the brush
toward the occlusal surface using a rolling stroke.
Disadvantages:
1- Brushing too high during initial placement can lacerate the alveolar mucosa.
2- Gingival sulcus areas are not cleaned properly, therefore additional efforts
for sulcus cleaning are required.
2- Vibratory technique:
It is most widely accepted and most effective method for dental plaque
removal, adjacent and directly beneath the gingival margin.
Indications:
1- For all patients for plaque removal adjacent to and directly beneath the
gingival margins.
2- Adaptable for open interproximal areas.
3- Recommended for routine patients with or without periodontal
involvement.
Technique:
With bristles pointed at a 45-degree angle into the gingival sulcus, vibrate the
brush gently back and forth about 20 times. Move the brush forward and
repeat.
Disadvantages:
1- May cause injury to the gingival margin.
2- Time consuming.
3- Dexterity requirement is too high for certain patients.
3- Circular technique:
Indicated for young children who want to do their own brushing or others with poor
manual dexterity.
Technique:
First, occlude the teeth. Then, lightly press the bristles against the posterior teeth
and the gingiva. Revolve the brush head in a fast, circular motion, using circles of
large diameter. Continue the circular motion, and slowly move the brush head
toward the anterior until all facial surfaces have been brushed. With the mouth
open, use the same circular motion on the maxillary and mandibular lingual
surfaces.
Advantages:
1- Easy to learn.
2- Shorter time.
3- Can be use for physically or emotionally handicapped individuals.
4- Patient who lack dexterity for more technical brushing method.
Disadvantages:
1- Possible trauma to gingival.
2-Inter dental areas are not properly cleaned.
4- Vertical technique:
In which maxillary and mandibular teeth are brushed separately.
Technique:
The bristles are placed at 90º angle to the facial surface of the teeth. The motion
is vertical up and down brushing movements on the facial surface of the clenched
anterior and posterior teeth. With the teeth edge to edge, place the brush with the
filaments against the teeth at right angles to the long axes of the teeth. Brush
vigorously, without great pressure with a stroke that is mostly up and down on the
tooth surfaces with just a slight rotation or circular movement after striking the
gingival margin with
force.
Advantage:
Most convenient and effective for small children deciduous teeth.
Disadvantage:
Inter dental spaces of the permanent teeth of the adults are not properly cleaned.
5- Horizontal technique:
Disadvantages:
1- In effective at plaque removal.
2- Tooth abrasion and gingival recession.
Technique:
The bristles of the toothbrush are placed perpendicular to the crown of the tooth,
the brush is moved back and forth in the horizontal movements on surfaces of the
teeth.
6- Physiological technique:
Technique:
Bristles are pointed incisally or occlusally and the along and over the tooth
surfaces and gingival.
The motion is gentle sweeping from incisal or occlusal surfaces over the facial
surfaces and progressing toward and over the gingiva.
Advantages:
1- Natural self cleansing mechanism.
2- Supra-gingival cleaning is good.
Disadvantage:
Inter dental spaces and sulcus areas of teeth are not properly cleaned.
Lecture 14
Types of Tooth brushes and
dental floss
History of the toothbrush: ancient people chewed twigs from plants with high
aromatic properties. These twigs freshened the breath.
The Arabs before and after Islam used a piece of the root of the arak tree
because its fibers stood out like bristles. This device was called a siwak. After
several uses, the bristle fibers became soft. To this day, the Arabs still use the
siwak, which is composed from aromatic types of
wood.
Types of toothbrushes:
two types available:
1- Manual toothbrushes.
2- Electric tooth brush
1- Manual tooth brush
Parts of manual toothbrush:
1- handle: the part grasped in the hand during tooth brushing.
2-head: the working end of a toothbrush that holds the bristles.
3-tufts: clusters of bristles secured into head.
4- shank: the section that connects head and handle.
Tooth brush bristles types:
1- Hard and soft.
2- Natural and synthetic.
3- Multitufted and space tufted.
The nylon bristle and the natural (hog), nylon bristle is superior to the natural one in
several aspects. Nylon bristles flex as many as 10 times more than natural bristles
before breaking, nylon is cheaper than natural one and not gets contaminated. The
only advantage that can be cited for the natural bristle is that its extreme flexibility
when wet.
The stiffness of bristles vary based on the following factors:
1- Diameter of bristles: bristles wider in diameter are stiffer as compared to bristles
with a lesser diameter.
2- Length of bristles: stiffness of the bristle is inversely proportional to its length,
shorter bristles are stiffer as compared to longer bristles.
3- Number of filaments in a tuft: each filament gives support to adjacent filaments
and each tuft gives support to adjacent tufts.
4- Curvature of filaments: curved filaments may be more flexible and less stiff than
straight filaments of equal length and diameter.
Self test (1) what are the tooth brush bristles?
Check your answers in the key answer page at the end of module.
2- Powered toothbrushes:
Alternative to manual brushes and make tooth brushing faster and efficient, they
also known as automatic or electric tooth
brushes.
Indications for powered tooth brushes:
1- Young children.
2- Handicapped patients.
3- Individuals lacking manual dexterity.
4- Patients with prosthodontic implants.
5- Orthodontic patients.
6- Elderly patients.
Advantages of powered tooth brushes:
1- It increases patient motivation resulting in better patient compliance.
2- Increased accessibility in inter-proximal and lingual tooth surfaces.
3- No specific brushing technique required.
4- Uses less brushing force than manual toothbrushes.
Power source:
1- Direct: cord from electrical outlet connects directly to tooth brush handle.
2- Replaceable batteries.
3- Rechargeable.
4- Switches.
Maintenance of tooth brushes:
1- Cleaning the tooth brush daily in antiseptic mouthwashes such as phenolic
derivatives.
2- Storing tooth brushes in dry areas (wet surfaces allow bacterial
proliferation).
3- Keep tooth brushes in open air with the head in an upright position with no
contact with other brushes.
Toothbrushes should be replaced each three months.
Dental flossing:
Silk floss is wrapped around two fingers and gently pulled backwards and
forwards between the teeth, taking care to avoid damage to the gingiva.
Types of dental floss:
Several types of floss are available:
1- Waxed and unwaxed.
2- Twisted and non twisted.
3- Thin and thick.
The degree of plaque control achieved by any type of floss is similar. However,
unwaxed floss is frequently recommended because it is thinner and slips more
easily through tight contact areas. Waxed dental floss, is benefit in an interdental space without tight contact points. Thin flosses are preferred by those
who have tight contact area.
Self test (2)
Enumerate types of dental floss?
Check your answers in the key answer page at the end of module.
Lecture 15
Slides show for brushing method
and inter-dental aids
Dental plaque etiology
Dental plaque is a soft, sticky film that
forms on the teeth EVERY DAY! It is made
up mostly of BACTERIA, which are ALIVE,
just like we are alive. Part of being alive is
that the bacteria eat, digest, and
metabolize their food and excrete the
waste products.
What’s more, the waste from some of the bacteria is
TOXIC WASTE, and these toxins can cause tooth
decay and gum disease when present in large
enough quantities. AND, if the plaque isn’t
removed, the bacteria can eventually invade the
gum tissue and enter the blood stream, where they
can travel to other parts of the body and lead to
more serious health problems.
Tooth brushing method
Place bristles along the gumline at a
should
Bristles
angle.
45-degree
contact both the tooth surface and
the gumline
Maintain a 45-degree angle with
bristles
contacting
the
tooth
surface and gumline. Gently brush
using
back,
forth,
and
rolling
motion along all of the inner tooth
surfaces.
Tilt brush vertically behind
the front teeth. Make several
up & down strokes using the
brush.
the
of
half
front
Place
the
brush
against
the
biting surface of the teeth & use
a gentle back & forth scrubbing
motion. Brush the tongue from
back to front to remove odorproducing bacteria.
The correct method of flossing
Lecture 16
Deposit retention factors
Deposit retention factors:
A variety of factors are responsible for the retention of soft deposits, calculus, and
extrinsic stains on the teeth, these are:
1- teeth:
A. Tooth surface irregularities:
Plaque may be attached to a defective or rough surface including:
1- Pits, fissures, cracks.
2- Calculus.
3- Exposed cementum: necrotic, resorbed and other irregularities.
4- Dental caries and decalcification.
5- Iatrogenic, like:
a. rough or grooved surface left after scaling.
b. inadequately polished dental restoration.
B. tooth contour:
1- Congenital abnormalities like extra or missing cusp.
2- Teeth with flattened proximal surfaces have faulty contact with adjacent teeth, permitting
deposits to wedge between.
3- Area of erosion and abrasion.
4- Large carious lesion.
5- Large deposit of calculus.
C- restorations:
1- Under contoured, over-contoured and restorations with faulty margins.
2- Dental appliances:
a. orthodontic appliances.
b. fixed bridge with different gingival margin of an abutment tooth.
c. removable partial denture, inadequately adapted clasps.
D. Position of teeth:
1- Mal occlusion. Irregular alignment of teeth or single tooth leave areas prone to collection
of plaque (crowded or overlapped, rotated, deep anterior
overbite).
2- Related to missing or extracted teeth (inclined or migrated, contact area usually
missing).
3- Related to eruption (incomplete eruption, below line of occlusion, partially erupted
impacted third molar).
2- Gingiva:
a. deviation from normal position (receded, reduced height of inter-dental papilla leaves
open inter-dental area, sub-gingival calculus provide rough
area).
b. deviation in size and contour (enlarged or cratered gingiva creates retentive area at
gingival crest).
c. deviation in surface texture (poor and inadequate keratinization make gingival susceptible
to laceration and subsequent bleeding which release blood elements for deposition on tooth
surface.
3- Saliva:
a. decreased quantity: limits cleaning and lubricating effects.
b. stagnation of saliva.
4- Mastication (unilateral chewing).
5- Mouth breathing: dehydration of oral tissues results in insufficient lubrication.
6- Dietary and eating habits:
a. physical character of diet:
1-soft, moist food (adhere to tooth surface and encourage plaque
formation).
2-firm, fibrous foods (are effective in mechanical cleaning of middle and incisal or occlusal
thirds of crowns but do not remove dental plaque from the cervical
third.
b. diet selection: sucrose in the diet increase amount of plaque and its bacterial
content.
7- Drugs, tobacco:
Certain drugs alter quantity of saliva.
Tobacco:
1- increased plaque and calculus.
2-contain tar products which stain teeth.
8- Personal oral habits:
a. inadequate brushing of less accessible areas encourages plaque and debris retention in
those areas.
b. incorrect use of tooth brush, dental floss may result in reduction in height of inter
dental papillae.
Lecture 17
Salivary glands, definition, location
Definition of salivary gland: a gland that secretes saliva, whose secretions enter the
mouth. The salivary glands are located in the region of the mouth, face and neck.
Types of salivary glands:1-major salivary gland, 2-minor salivary gland.
Major salivary glands:
There are three pairs of major saliva glands:
1-The Parotid glands are the largest of the salivary glands on the sides of the jaw just
below and in front of the ears. They are the "pickle glands" that create that funny feeling
on the sides of your face when you first taste something really sour. The reason we feel it
is that the parotids are contracting, expressing a sudden burst of saliva into the mouth. The
glands empty through tiny holes in little bumps on the inside of the cheeks. These bumps
are called Stenson's ducts and we can feel them with the tip of your tongue on the cheeks
on either side of your mouth beside the upper back molars.
2-Submandibular Glands
The submandibular glands are a pair of glands located beneath the lower jaws, superior
to the digastric muscles. The secretion produced is a mixture of both serous fluid and
mucus, and enters the oral cavity via Wharton's ducts. Approximately 70% of saliva in
the oral cavity is produced by the submandibular glands, even though they are much
smaller than the parotid glands.
3-Sublingual Gland: The sublingual glands are a pair of glands located beneath the
tongue to the sub-mandibular glands, it is the smallest of salivary glands.
The secretion produced is mainly mucous in nature, however it is categorized as a
mixed gland. Unlike the other two major glands, the ductal system of the sublingual
glands do not have striated ducts, and exit from 8-20 excretory ducts. Approximately
5% of saliva entering the oral cavity comes from these glands.
Minor Salivary Glands:
There are over 600 minor salivary glands located throughout the oral cavity
within the lamina propria of the oral mucosa. They are 1-2mm in diameter and
unlike the other glands, they are not encapsulated by connective tissue only
surrounded by it. The gland is usually a number of acini connected in a tiny
lobule. A minor salivary gland may have a common excretory duct with another
gland, or may have its own excretory duct. Their secretions are mainly mucous
in nature (except for Von Ebner's glands) and have many functions such as
coating the oral cavity with saliva. Problems with dentures are usually
associated with minor salivary glands. The function of the minor salivary
glands is to produce and excrete the saliva and mucus needed for chewing and
digestion.
Lecture 18
Saliva, definition, composition, role
of saliva in dental caries, gingivitis
Definition of saliva: is a complex mixture of several components, whole saliva is formed
from salivary gland secretion, but also contains gingival fluid, desquamated epithelial cell,
bacteria, and possibly food debris, blood and
viruses.
Function of saliva:
1- Protects the oral tissues.
2- Protects teeth and soft tissue in the mouth.
3- Protects against infection.
4-Facilitate eating and speech.
5- Oral clearance, cleansing by washing away food debris from the mouth and
teeth.
6-Ion reservoir all elements in saliva help in remineralization of teeth.
7- Buffer, neutralized acid produce by bacteria.
Composition of saliva:
Water (99.4-99.5).
Organic.
Inorganic (electrolytes).
Salivary flow rate
Diminished salivary output can have deleterious effects on oral and systemic
health. Unstimulated whole saliva is the mixture of secretions which enter
the mouth in the absence of exogenous stimuli such as tastants or chewing.
In unstimulated saliva the average value of flow rates for whole saliva in
healthy individuals have found be about 0.3 ml/min. Values below 0.1 ml/min
are considered as hyposalivation, and values between 0.1-0.25 ml/min is
considered low. Xerostomia (dry mouth) is the subjective feeling of oral
dryness. It is generally accompanied by salivary gland hypofunction and a
severe reduction in the secretion of unstimulated whole saliva. The factors
affecting unstimulated saliva flow rate are degree of hydration, body
position, exposure to light, previous stimulation, and drugs. Widely accepted
normal values for stimulated flow rates are 1.0 - 3.0 ml/min. Values below
0.7 ml/min are considered as hyposalivation, and values 0.7 – 1.0 ml/min
low.A wide variation among individuals has been found.
Men have higher flow rates than women. The factors affecting the flow of
stimulated saliva are nature of stimulus, vomiting, smoking, gland size, gag
reflex, and food intake. Reduced salivary flow may cause a variety of mostly
unspecific symptoms to the patient, so the establishment of salivary flow rates
is of primary importance in oral medicine and dentistry. Saliva influences
caries attacks mainly by its rate of flow and its fluoride content. The salivary
flow rate influences to a high degree the rate of oral and salivary clearance of
bacterial substrates.
Buffering capacity of saliva:
Salivary buffering capacity is important in maintaining a pH level in saliva and
plaque. The buffer capacity of unstimulated and stimulated whole saliva
involves three major buffer systems. The most important buffering system in
saliva is the carbonic acid / bicarbonate system. The second buffering system is
the phosphate system, which contributes to some extent to the buffer capacity
at low flow rate. The third buffering system is the protein system. In the low
range of pH the buffering capacity of saliva is due to the macromolecules
(proteins) containing H-binding sites. The bicarbonate concentration is strongly
dependent on secretion rate. Since bicarbonate is the chief determinant of the
buffer capacity, there is an interrelationship between pH, secretion rate and
salivary buffering capacity.
The lubricating action of saliva is important for oral health. It facilitates the
movements of the tongue and the lips during swallowing and eating and is
important for clearly articulated speech. Increased salivary viscosity may also
be associated with an increase in dental caries.
Immune system (specific and non specific):
Specific immune system ( immunoglobulins like IgA, Ig M)
Functions of immunoglobulin in general are inhibition of bacterial adherence,
agglutination of bacteria.
Non specific immune system ( lysozyme, mucins, lactoferrin):
Lyzozyme function lyse many cariogenic and non cariogenic streptococci.
Mucins inhibit bacterial adhesion to soft tissue surface.
Lactoferrin binding to ferric ion which is necessary for nutrient of microorganism.
The role of saliva in dental caries:
1- It has a buffering effect for the produced acid after ingestion of sugar
increasing the flow and acid dilution and by increasing the concentration of the
bicarbonate buffer to neutraliz these acids.
2- It maintains a concentration gradient for calcium and phosphate ions
providing a powerful remineralizing mechanism.
3-The presence of antibacterial systems in saliva such as lyzozyme, lactoferrin
which are active against many species of bacteria.
The role of saliva in periodontal disease:
1- Calculus formation is formed on tooth surfaces opposite to salivary glands
ducts which give rise to irritation gingiva and cause gingivitis.
2- Saliva and gingival fluid also serve to remove bacteria and their products by
mechanical cleaning.
3- The presence of immunoglobulin in saliva play a major role in defense
against infection.
Age changes with saliva:
1- Phosphorous and calcium concentrations tend to increase and this
corresponds with increased amount of calculus in older persons.
2- Sodium and potassium concentrations also increase.
3- Viscosity is lower than those younger ages.
lecture 19
Indices used for
assessment of dental caries
1-Decayed- missing- filled teeth Index (DMFT Index):
It was developed in 1938, it is a simple, rapid and applicable measurement, this
index based on the fact that when caries occur the tooth either remains
decayed or if treated it is extracted or filled.
The examination should be done:
1- Under good lighting conditions.
2- Using plain mirror.
3- Dental explorer.
The DMFT Index is applied only to permanent teeth is composed of three
components, the D- component for (Decayed), the M- component for (Missing),
and the F- component for (Filled).
All the 28 permanent teeth are examined.
D- Component (Decayed tooth)
1- Carious tooth.
2- Filled tooth with caries.
3- Retained root.
4- Temporary restoration.
5- Defect filling.
6- Filled tooth surface with other surface decayed.
M- Component (missing due to caries)
Excluding
Extracted tooth for reasons other than dental caries (orthodontic reason,
impaction, periodontal reason.
Unerupted teeth.
Congenitally missing.
Avulsion teeth (trauma).
F-component (filling due to caries)
Excluding
1- Trauma.
2- Fissure sealant.
3- Seal a root canal due to trauma.
4- Abutment tooth (bridge).
5- Preventive filling.
6- Hypoplasia.
Calculation of DMFT Index:
1- Individual
Ex. 5 teeth are decayed
2 teeth missing
5 teeth are filled
D+M+F= DMFT
5+2+5= 12
2- population:
Total DMF
Average DMF =
Total number of subjects examined
Maximum score= 28
Excluding teeth (DMFT Index)
1- Third molars.
2- Unerupted teeth.
3- Congenital missing teeth.
4- Supernumerary teeth.
5- Extracted teeth (orthodontic reason, impaction, periodontal diseases).
2-DMFS Index:
It is use to measure dental caries according to surfaces.
Maximum score= 128
It counts
For posterior teeth as 5 surfaces
For anterior teeth as 4 surfaces
3-dmft and dmfs Indices use for primary teeth
Maximum score for dmft= 20, for dmfs= 88.
lecture 20
Oral Hygiene Indices
1- Plaque index: (PlI): Introduced in 1964
Wisdom teeth are excluded.
Used on all teeth or selected teeth.
No substitution for any missing tooth.
Used on all surfaces(4) or selected surfaces.
Maximum score is 3
The six index teeth are:
6
1
4
Score
criteria
0
no plaque
1
a film of plaque adhering to the free gingival
margin which cannot be seen with the naked eye. Only by using
probe.
2
eye.
3
moderate accumulation of dental plaque can be seen by naked
thick layer of dental plaque.
Total scores
Calculation =
No. of surface examined
This index measures the thickness of plaque on the gingival one third.
Calculation :
1- individual:
Total scores
PlI =
No. of surfaces examined
2- population:
Total scores
PlI =
No. of subjects examined
2- Index used for calculus assessment:
Calculus index this index measures the extension of calculus.
Maximum score is 3
Score
criteria
0
no calculus
1
Supra gingival calculus covering not more than one third
of the tooth surface.
2
Supra gingival calculus covering more than one third of
the tooth, but not more than two thirds of the tooth
surface.
3
supragingival calculus covering more than two thirds of
the
tooth
Surface,
in
addition
to
the
presence
of
subgingival calculus
3-Indices used for gingival disease assessment:
Gingival index (GI): Which was introduced in 1963, this index measure the
severity of gingivitis.
It could be used in all teeth or selected teeth and in all surfaces or selected
surfaces.
The examination done by blunt probe.
Partially erupted teeth, retained roots, teeth with periapical lesion and
third molars should be excluded and there is no substitution.
Score
Criteria
0
no inflammation
1
mild inflammation, slight change in color, slight
edema, no bleeding on probing.
2
moderate inflammation, redness, edema , bleeding on
probing.
3
severe inflammation, marked redness, ulceration,
tendency to spontaneous bleeding.
lecture 21
CPITN Index (community
periodontal index of treatment
needs
Introduction about the index:
This is a newly developed index by the WHO to screen periodontal disease and the
treatment needs. This index was introduced in 1982.
The method of recording the CPITN:
The probe used in this index designed to serve two purposes, namely measuring of
pocket depth and detection of subgingival calculus. The probe has a metal handle and
ball tip of 0.5 mm diameter. The CPITN probe ends with a small ball. The probe is
used to see the depth of gingival sulcus. It has markings on its surface to show
various levels of the gums. There is usually a black band that makes it easier for the
common distinction between health and disease. Then the severity can be seen
according to how much is left of this black band or if it completely disappears. This is
an area where the gum contacts the tooth ad it is here that plaque accumulates. In
health these pockets are never more than 3mm but in disease states the pockets can
become deeper. The CPITN probe measures these pockets and is used to indicate
what sort of treatment is needed.
The color coded area from 3.5-5.5 greatly facilitates rapid reading of pocket
depth.
The periodontal treatment needs are recorded for sextants i.e. sixths of the
dentition.
If any tooth is missing the distal neighbor is used as a substitute.
Third molar are excluded
In epidemiological survey
Less
6
6
1
6
6
1
20 y
more
76
76
1
1
67
67
In dental practice
All teeth in the sextant are examined, only the highest score is recorded for each sextant.
all
all
all
all
all
all
Recording:
Score
criteria
0
no periodontal disease.
1
bleeding on probing.
2
calculus with plaque seen or felt by probing.
3
pathological pocket 4-5 mm.
4
pathological pocket 6 mm or more.
X
when only 1 tooth or no tooth are present in a sextant.
Treatment needs are classified according to the findings scores:
Score
criteria
0
no need for treatment.
1
personal plaque control (OHI).
2
professional plaque control (scaling and polishing).
3
prfessional and personal cleaning of teeth and oral hygiene
instruction.
4
complex treatment (deep scaling and root planning) or
surgical procedures.
Lecture 22
Curative treatment for
dental caries:
The treatment of dental caries by conservative Dentistry means filling the defect
in enamel or dentin by a restoration.
Definition of dental restorative materials: are specially fabricated materials,
designed for use as dental restorations (fillings), which are used to restore tooth
structure loss.
Types of restorative materials:
1-Direct restorative materials
The chemistry of the setting reaction for direct restorative materials is designed
to be more biologically compatible. Heat and byproducts generated cannot
damage the tooth or patient, since the reaction needs to take place while in
contact with the tooth during restoration. This ultimately limits the strength of the
materials, since harder materials need more energy to manipulate.
a.Amalgam
Amalgam is a metallic filling material composed from a mixture of mercury
(from 43% to 54%) and powdered alloy made mostly of silver, tin, zinc and
copper commonly called the amalgam alloy. Amalgam does not adhere to tooth
structure without the aid of cements. Amalgam is still used extensively in many
parts of the world because of its cost effectiveness, superior strength and
longevity. However their metallic colour is not aesthetic and tooth coloured
alternatives are continually emerging with increasingly comparable properties.
Due to the known toxicity of the element mercury, there is some controversy
about the use of amalgams.
b. Composite resin
Composite resin fillings (also called white fillings) are a mixture of powdered
glass and plastic resin, and can be made to resemble the appearance of the
natural tooth. They are strong, durable and cosmetically superior to silver or
dark grey colored amalgam fillings. Composite resin fillings are usually more
expensive than amalgam fillings. Most modern composite resins are lightcured photopolymers, meaning that they harden with light exposure. They can
then be polished to achieve maximum aesthetic results. Composite resins
experience a very small amount of shrinkage upon curing, causing the
material to pull away from the walls of the cavity preparation. This makes the
tooth slightly more vulnerable to microleakage and recurrent decay.
Generally, composite fillings are used to fill a carious lesion involving highly
visible areas (such as the central incisors or any other teeth that can be seen
when smiling).
c. Glass Ionomer Cement
These fillings are a mixture of glass and an organic acid. Although they are
tooth-colored, glass ionomers vary in translucency. Although glass ionomers
can be used to achieve an aesthetic result, their aesthetic potential does not
measure up to that provided by composite resins.
The cavity preparation of a glass ionomer filling is the same as a composite
resin; it is considered a fairly conservative procedure as the bare minimum of
tooth structure should be removed. Conventional glass ionomers are
chemically set via an acid-base reaction. Upon mixing of the material
components, there is no light cure needed to harden the material once placed
in the cavity preparation. After the initial set, glass ionomers still need time to
fully set and harden.
Glass ionomers do have their advantages over composite resins:
1. They are not subject to shrinkage and microleakage, as the bonding
mechanism is an acid-base reaction and not a polymerization reaction.
2. Glass ionomers contain and release fluoride, which is important to preventing carious
lesions. Furthermore, as glass ionomers release their fluoride, they can be "recharged"
by the use of fluoride-containing toothpaste. Hence, they can be used as a treatment
modality for patients who are at high risk for caries. Newer formulations of glass
ionomers that contain light-cured resins can achieve a greater aesthetic result, but do not
release fluoride as well as conventional glass ionomers.
d. Resin modified Glass-Ionomer Cement (RMGIC)
A combination of glass-ionomer and composite resin, these fillings are a
mixture of glass, an organic acid, and resin polymer that harden when light
cured. (The light activates a catalyst in the cement that causes it to cure in
seconds.) The cost is similar to composite resin. It holds up better than glass
ionomer, but not as well as composite resin, and is not recommended for biting
surfaces of adult teeth. In general, resin modified glass-ionomer cements can
achieve a better aesthetic result than conventional glass ionomers, but not as
good as pure composites.
e. Compomers
a combination of Composite resin and glass ionomer technology, however with
the focus lying towards the composite resin end of the spectrum. Has better
mechanical and aesthetic properties than RMGIC but worse wear and requires
a bonding system to be used. Although compomers release fluoride, they do so
at such a low level that it is not deemed effective.
2-Indirect Restorative materials
a.Porcelain (ceramic)
Porcelain fillings are hard, but can cause wear on opposing teeth. They are
brittle and are not always recommended for molar fillings.
b. Gold: Gold fillings have excellent durability, wear well, and do not cause
excessive wear to the opposing teeth, but they do conduct heat and cold, which
can be irritating.
lecture 23
Minimally Invasive Dentistry
Definition of 'Minimally Invasive Dentistry:
The concept 'Minimally Invasive Dentistry' can be defined as maximal preservation of
healthy dental structures. Within cariology, this concept includes the use of all available
information and techniques ranging from accurate diagnosis of caries, caries risk
assessment and prevention, to technical procedures in repairing restorations. Dentists
are currently spending more than half their time replacing old restorations. The main
reasons for restoration failures are secondary caries and fractures.
Early caries detection:
Detection of the carious lesion is only one aspect in the diagnosis of caries. Caries
activity which may be even more important also must be determined but often is
difficult to assess. Caries activity is the process that begins with the presence of
attached dental plaque, which leads to demineralization of the underlying tooth
structure. It is important to remember that caries activity cannot be determined at one
point in time, it must be determined by monitoring the lesion over time. Radiographs
and clinical information usually are used to make this determination, though other
diagnostic tools are emerging.
Some methods are better for detecting occlusal caries, while others are better for
detecting proximal or smooth-surface lesions. These emerging technologies include
electrical conductance methods, quantitative laser fluorescence, laser fluorescence,
computed tomography.
Remineralization of early lesions and reduction of cariogenic bacteria:
It now is well-recognized that it is possible to arrest and even reverse the mineral loss
associated with caries at an early stage, before cavitation takes place. Enamel and
dentin demineralization is not a continuous, irreversible process. Through a series of
demineralization and remineralization, the tooth alternately loses and gains calcium
and phosphate ions, depending on the microenvironment. Fluoride enhances the
uptake of calcium and phosphate ions and can form fluoroapatite, making it more
resistant to demineralization from an acid challenge than hydroxylapatite. In early
carious lesions, there is subsurface demineralization of the enamel.
As caries progresses into dentin, the surface of the enamel eventually cavitates. Once
cavitation occurs, it becomes difficult to control plaque accumulation. In areas of
difficult access, the plaque also may hinder the availability of calcium, phosphate and
fluoride ions, which in turn may decrease the potential for remineralization. Therefore
surgical treatment— caries removal and restoration is indicated for the cavitated lesion.
In the noncavitated lesion, to take advantage of the tooth’s capacity to remineralize,
one must first alter the oral environment, to tip the balance in favor of remineralization
and away from demineralization.
This approach includes decreasing the frequency of intake of refined carbohydrates;
ensuring optimum plaque control, ensuring optimum salivary flow, conducting patient
education. Agents such as chlorhexidine and topical fluorides then can be applied to
encourage remineralization. Chlorhexidine acts by reducing the number of cariogenic
bacteria. Topical fluorides increase the availability of fluoride ion for remineralization
and the formation of fluoroapatite, with its increased resistance to demineralization.
Minimal tooth preparation:
Many conventional preparations are based upon a philosophy of extension for
prevention and the needs of the restorative material rather than the health of the tooth.
Minimally invasive dentistry utilizes techniques and materials to access caries that
cannot be remineralized and to restore the tooth with minimal loss of healthy structure.
Sealants are used as a preventive measure for pits and fissures likely to become carious.
When caries is present, small composite restorations referred to as "preventive resin
restorations" offer a more conservative preparation than the large amalgam preparation,
which requires healthier tooth structure be removed. Pits and fissures are minimally
prepared to remove demineralized enamel and dentin, and then restored with resinbased composite. Unaffected fissures are cleaned of organic debris and sealed. Bonding
with adhesive resins retains the restorations rather than mechanical retention from
undercuts and dovetails. Extensions into embrasures are not made unless dictated by the
caries. Undermined enamel is not removed unless it is very thin, as it will be supported
by bonded composite resin.
Air abrasion: -Air abrasion is a technique that uses kinetic energy to remove carious
tooth structure. A powerful narrow stream of moving aluminum oxide particles is
directed against the surface to be cut. When these particles hit the tooth surface, they
abrade it, without heat, vibration or noise. The particles exit at the tip of the handpiece,
so it is an end-cutting device.
Clinical applications:
Specific indications for use of air abrasion are caries removal; restoration preparation;
cutting and etching tooth structure for the placement of composites, porcelain and
ceramics; and as an adjunct to the dental drill and handpiece bur.
Clinical limitations: Air abrasion is not well-suited for removal of amalgam and gross
caries. Air abrasion is not an efficient means of removing large amalgams and there is
concern for the levels of mercury released when amalgam is abraded.
Air abrasion is also not effective for removal of gross caries because it does not cut
substances that are soft or resilient well.
Care must be taken when working near soft tissues due to risk of laceration, air
dissection and emboli. An inadvertent spray to soft tissues is not likely to cause
damage, but a prolonged direct spray could potentially cause injury. When used
properly, risk of adverse events is extremely low. Air abrasion cannot be used for all
patients. It should be avoided in cases involving severe dust allergy, asthma, chronic
obstructive lung disease, recent extraction or other oral surgery, open wounds,
advanced periodontal disease, recent placement of orthodontic appliances and oral
abrasions, or subgingival caries removal. Many of these conditions increase the risk of
air embolism in the oral soft tissues.
Before air abrasion and restoration
After preparation with air abrasion
Laser cavity preparation:
Lasers are being used to cut dental hard tissues. These lasers can remove soft caries, as
well as hard tissue. Lasers reportedly can allow the dentist to remove caries selectively
while maintaining healthy dentin and enamel. They also can be used without
anesthetic most of the time. Advantages include no vibration, little noise, no smell and
no numbness associated with anesthesia. When dental lasers are used correctly,
excessive heat generation and its detrimental effects on dental pulp can be
avoided.
Materials used in minimally invasive procedure:
Adhesive dental materials make it possible to conserve tooth structure using
minimally invasive cavity preparations, because adhesive materials do not
require the incorporation of mechanical retention features. There are several
materials that can be used: glass ionomer cements, or GICs, resin-based
composite/dentin bonding agents.
lecture 24
Prosthesis, Definition, Types
and Care for dental
appliances:
Prosthesis, Definition, Types and Care for dental appliances:
Definition of prosthesis: When teeth are lost due to any disease, the replacement is
necessary by dentures constructed to replace missing teeth, which are supported by the
surrounding soft and hard tissues of the oral cavity.
Types of prosthesis:
1-Fixed prosthesis (crown and bridge).
2-Removable prosthesis.
The fixed partial denture (is the ideal prosthesis for the replacement of the lost
dentition
while
the
second
choice
is
the
removable
partial
denture).
Advantages of the removable partial denture over the fixed prosthesis:1- There are fewer appointments needed, less intra oral procedures required, frequently
the appliance may be constructed at a lower cost, oral hygiene is more readily
maintained by the patient.
2- The removable partial appliance restores a large span of lost dentition, for example
the distal extension in a quadrant usually spans from the cuspids to the second molar.
3- The removable appliance adapts to the mouth of children and adults, the removable
partial denture avoid reducing tooth structure on primary or permanent dentition.
4- The removable partial denture serves as a stimulus to the teeth having a periodontal
condition by providing support after periodontal surgery.
5-The appliance provide stimulus to the mucosa and alveolar ridge through the saddle
resting over the bridge.
The fixed bridge needs reduction of the tooth substance to provide retention for fixed
prosthesis.
Care for dental appliances:
A daily routine of cleaning and maintenance will help keep the dentures feeling and
looking good for a long time to come.
1- Daily denture care:
Proper denture care begins with the removal of denture plaque. Plaque is a sticky,
colorless film composed of colonies of bacteria, it tends to form on all dentures as it
does on natural teeth.
Stain comes from tobacco, coffee, tea and many other foods, they stick to plaque
easily and they are hard to remove. To prevent plaque buildup and the stain that
usually follows. Prosthesis must be cleaned to be sure that the cleaning product you
use is effective in removing plaque.
2- Brushing:
Brushing is the best way to remove denture plaque, however, great care must be
taken to protect the delicate surface of the dental work. So that why it is important
that brushing should be done with the cleanser that is low in abrasion and at the
same time, effective in removing plaque and stain.
3- Soaking:
Soaking is important, the dental work recommended to be taken out at night to
rest the denture- bearing tissues. However denture material can dry out when
removed from the moist environment of the mouth. That is why dental work
should be put in water when they are not in use. Adding a suitable denture
cleanser to the water is a good idea because it helps dentures fresh and odor
free.
Lecture 25
Plaque control: instruction procedure,
individual patient program, presentation,
demonstration
Plaque control in the individual is directly related to the cleaning the teeth on regular
basis. The most effective means of plaque removal available at present is mechanical
(tooth brushing) and to a lesser extent by flossing. Since pellicle begins to form
immediately and plaque forms again within ten to 24 hours following its removal, it
is evident that self care measures for control are necessary on a day to day basis.
Personal measures for plaque control need supplementation by professional care
measures such as removal of dental calculus and other irritants to create an
environment
which
can
be
effectively
maintained
by
the
individual.
Instruction procedure for individual patient:
Instruction need to be planned if it is to stay directed towards goals. The design of
instructions may be divided into certain basic steps:
a. objectives
b. presentation
c. demonstration
d. practice
e. evaluation
If the patient is to participate effectively in the learning process, he must be
involved in setting his own goals.
1. Selection of objectives:
Patient history, oral inspection, radiographs, study casts and all other data are
collected during the initial evaluation and diagnosis, details of the self-care
program are included. The factors considered for tooth brush selection are
included for the total program, these factors including:
a. teeth
b. gingival
c. general health
d. age:
1- Pre-school child requires parental assistance.
2- Motivation varies with age.
e. dexterity: For most patients dexterity cannot be detected until after instruction
has begin.
f. motivation factors
2- Program outline:
a. program planning: these include selection of tooth brush, tooth brushing
method, inter-dental care, devices and methods, with a clear definition of the
needs of the patient. The patient is shown his oral condition, changes and benefits
which
can
be
expected
are
explained
and
cooperation
is
needed.
b. immediate and long term programs: the immediate program is related to the
treatment phase and is complicated and intensified while the long term program is
related to maintenance phase of care and is less complicated or
intensified.
The new habits and attitudes acquired during the immediate program phase may
aid to the transition to the long term program.
3-Presentation, demonstration, practice:
1- With the disclosing agent, a method of instruction is available.
2- Dental plaque is not visible on all teeth without staining it.
3- Instructions best given on dental chair because of the need of light and rinsing
facilities.
4- Specific area should be planned with mirrors for patient to use to observe stained
plaque on posterior teeth and distal surfaces. He should also be able to see the
placement of the tooth brush and floss in all areas of the
mouth.
5- Gingival index, plaque index or other plaque control records can be educational and
motivating for patients.
1- First lesson:
a. objective- orientation to dental plaque removal.
b. describe the formation and composition of dental plaque, its relation to oral disease
and particularly to patient condition.
c. illustrate: show tooth with gingival and where the plaque is collected, explain how
inflammation develop in gingival. The instruction should be divided for more than one
period.
d. demonstrate:
1. Patient to observe in a hand mirror a healthy area of gingival and inflamed one and
then compared.
2- With a probe pockets can be demonstrated.
3- Remove a sample of plaque to show its thickness.
e. disclosing agent:
1- Explain its purpose: discoloration of plaque to show where masses of bacteria
accumulate.
2- Apply disclosing agent by topical application, provide diluted concentrate for a
rinse, or request the patient to chew a tablet, swish for one minute and rinse.
3- Examine the teeth with patient pointing out the stained plaque and explain how
these areas (proximal surfaces and cervical third of teeth) are adjacent to gingival and
therefore bacteria should be removed to control inflammation.
4- Evaluation of location of disclosed plaque will benefit as a guide for plaque
removal.
f. plaque removal instructions:
1- Keep instruction simple.
2- Floss first:
a. Review objectives
b. show how to hold the floss, inserting proximally, pressing around the tooth and
activating for plaque removal.
c. examine by a mirror to observe areas where plaque have been removed.
3- brush: give patient a soft brush and ask him to remove the stained plaque, no
specific brushing instructions are given at this time so that patient can concentrate on
the single objective related to plaque removal.
4- After brushing examine the teeth with the patient and enable him to see that he was
able to remove accessible plaque.
g. continuation of appointment; instruction and practice of plaque removal should
occupy the first appointment and clinical services should not be started until gingival
clinical inflammatory signs have been lessened and the patient have shown good
progress in learning self- care.
h. end of appointment instruction:
1- Use disclosing agent at home. Provide patient with tablets or instructions for
purchasing.
2- Emphasize the need for cleaning regularly. Discuss carrying a tooth brush for use
when not at home.
3- Keep the brush that has been used that day in the office for use in future
appointments, write the name and number of the brush for patient to purchase for
home use.
Lecture 26
Patient motivation, and education, community
base and individual base
Definition of motivation: is part of a dental health education practice where an
individual is motivated to practice behavior that lead to achievement of goals which
be values.
Dental health instruction can be effective if the patient considers his oral health a
valuable goal.
Definition of dental health education:
Is the provision of oral health information to people in such a way that they can apply
it in everyday living.
Motivation factors for persistence of plaque control by the patient:
1- Previous oral health habits which can reveal present attitudes and motivation, but
frequently a lack of oral cleanliness can be related to a lack of knowledge. Many
people have had very little or no instruction in how to care for their mouth.
2- Long range motivation or prejudging a patient's motivation and willingness to
carry out prescribed procedures is rarely possible.
3- Motivation is directly related to the dental hygienist concern and enthusiasm.
Community motivation (the primary health care approach):
Where more participation of the community in the context of dental health. Public and
dental profession are both involved to improve oral health of people where extra
professional personals are involved such as teachers, tribe leaders, clergy men, women
representatives….etc. decision makers such as politicians, ministers…etc. can be
involved for central decisions such as water fluoridation, national food policy and
directory education on dental health care.
When the politicians are interested in dental health programs they will motivate their
ministries, government personnel, media and people organization to practice dental
care and proper hygiene practice. This will directly motivate the individuals for its
wide range influence on people.
Individual based motivation:
For most patients major emphasis needs to be placed on control of dental caries and
periodontal disease. Attention also to be paid to accident prevention particularly
related to mouth protectors for contact sports, safety belts for cars, and children
accidents which lead to fractured anterior teeth.
Patient instruction in the past concentrated on teaching the patient how to brash his
teeth, usually by means of model, and in one short session, but now they are of a wide
range of essential areas of learning aimed to develop patient attitudes and knowledge
and practices for continuing oral health.
Individual based motivation will lead after the change of knowledge, attitudes and
practices of the individual to be transferred from the individual to the family and then
to the community. To know and believe health facts is not enough, benefits results
only when knowledge is put into action. Learning occurs when an individual changes
his behavior and when changes are incorporated as a part of everyday
living.
Lecture 27
Patient motivation in control of
dental caries and periodontal disease
Patient motivation in control of dental caries:
Patient who are subject to marked dental caries activity are a particular responsibility
of the members of the dental profession. These patients and their parents when the
patient is a child need special help in coping with the problem if left unattended may
lead to an extensive and premature loss of teeth.
This requires a great effort and patience by the dentist and dental hygienist in
determining the method of approach, the method includes:
1- Help the patient analyze the problem and initiate a preventive program.
2- The information is similar to that given for all patients.
3- In addition to the patient history, oral inspection, radiographic survey, charting, a
study of diet and other initial evaluation procedures should be done.
4- A plan is made for elimination of foods with high sucrose content and also be aware
of the hidden sugar contents of many types of foods available in the market.
5- Personal care procedures by the patient are emphasized through diet control,
utilization of fluoride containing dentifrices, mouth rinses, and regular attendance to
the
dentist
for
application
of
fluoride
and
fissure
sealants.
6- Through dental health instructions, patient become educated about each step in the
prevention and accept responsibility in carrying out his part in the control program.
7- The success of any program is dependent on patient's clear understanding and
appreciation
of
the
procedures
and
his
willingness
to
cooperate.
8- In turn the dental hygienist applies knowledge of physical and emotional
problems at various age levels to try understand and motivate the
patient.
Patient motivation in control of periodontal disease:
Periodontal disease is plaque initiated disease and plaque control can influence
gingival and periodontal health so the patient motivation should be directed towards
dental plaque control.
The method is by:
1- Detection of dental plaque on tooth surface and showing it to the patient through his
direct vision or the use of explorer or the use of disclosing tablets.
2- Stating the objectives of the plaque control such as removal of calculus prior to
calcification, removing of plaque for control of gingivitis, decrease the possibility of
halitosis, oral comfort, sanitation and appearance with refreshed taste.
3- Presentation of the instructional methods that will be most helpful.
4- Demonstration of the sequence of steps used or to be learned.
5- Practice of the procedure in terms of knowledge and skills.
6- Evaluation of the patient self care procedures and patient efficiency.
Lecture 28
Smoking, alcohol, drug uses and
Oral Health
Major bad effects of smoking on oral health:
1-Tooth Discoloration: Most smokers are generally aware of the tooth stains that are
caused by smoking. These tooth stains are due to nicotine and tar present in the
cigarette. The staining ranges from yellow to dark brown (from years of smoking).The
staining can be on specific teeth or general discoloration. These stains are hard to
remove by normal brushing.
2-Bad Breath: Smokers are at a much greater risk of developing bad breath than nonsmokers. The nicotine and tar content gives rise to a typical bad breath known as
smoker's breath.
Apart from this smoking causes dry mouth which is a leading cause of Halitosis (bad
breath).
3-Tooth Decay: Smoking puts individual at a greater risk of developing dental caries
due to plaque buildup.
4- Gum Disease: Smoking also results in gum disease due to plaque and tartar build
up. Smoking also interferes with the normal functioning of the cells in the gum
tissue.
5- Tooth Loss: Advanced gum disease (Periodontitis) is the leading cause of tooth
loss in adults.
6- Oral Cancer: another major bad effect of smoking is oral cancer. Nearly 90% of
all Oral Cancer patients are smokers.
Minor bad effects of smoking on oral health:
Jaw bone loss
Shifting teeth
Hairy tongue
Sinusitis
Altered sense of taste and smell
Delayed wound healing
Smoking not only creates dental health issues but worsens already existing dental conditions.
Alcohol and oral health:
Drinking alcohol can cause:
Irritation of the gum, tongue and oral tissues.
Poor healing after dental surgery.
Poor dental health habits.
Increase in tooth decay.
Increases risk toward periodontal (gum) disease
Drinking is a risk factor for oral cancer.
Heavy drinker are at greater risk of developing cancer in the mouth, throat and
esophagus – as well as risking tooth decay from the increased exposure to sugars
and acids within the drink. People with alcohol abuse problems have been shown to
have a higher incidence of periodontal disease, tooth decay and potentially
precancerous oral lesions.
Drugs and Oral Health:
Medications have side effects that can affect oral health. Medications and drugs do
not exclusively go to the cells that are involved in the problem--instead they go to
tissues, blood, lymph, all cells and organs of the whole body, metastasizing side
effects to the whole system. There are many drugs that can cause serious side effects
that alter oral health. Some of these effects include:
Dry mouth
Permanent tooth discoloration
Gingival hyperplasia
Oral lesions
Abnormal bleeding
Jaw clenching
Teeth grinding
Dry Mouth: This can be caused by common antidepressants and anti-anxiety
medications, antihistamines, anti-inflammatory drugs and narcotics in addition to drugs
used for glaucoma and bladder spasms and urinary retention as well as
antihypertensives. When the mouth is chronically dry, the teeth, oral mucosa and soft
tissue are easily inflamed, painful and prone to infection. This environment commonly
leads to tooth decay and necrosis of the nerves innervating the teeth.
Tooth Discoloration: This is a common side effect of some antibiotics.
Gingival Hyperplasia: This is a condition defined as overgrowth of the gum tissue. It
is commonly caused by seizure medications, heart medications, medications for high
blood pressure and immunosuppressant medications.
Oral Lesions: This is defined as soft tissue discoloration and inflammation. This can
be caused by drugs used for blood pressure, immunosuppressants, oral contraceptives
and chemotherapy drugs.
Abnormal Bleeding: This can be caused by drugs such as aspirin, steroids and
anticoagulants, which are used to thin the blood in common conditions associated
with strokes and certain diseases associated with the heart and arrhythmias.
Jaw Clenching and Teeth Grinding: These can be side effects of antidepressants
and anti-anxiety medications. A diet rich in sugars and sugar-forming foods cultivate
the growth of parasites, viruses and bacteria. This affects our metabolism and
stimulates the nervous system causing it to be "over charged" and resulting in the
clinging and grinding of the jaw.
Lecture 29
Chemical plaque control ( mouth rinses )
Classification of chemical plaque control agents:
1-First generation antiplaque agents
Capable of reducing plaque by about 20-50%, ex. Antibiotic, phenols, these
products are less retained by oral tissues.
2- Second generation antiplaque agents:
Produce plaque reduction by about 70-90%, better retained by oral tissues and
exhibit slow release properties, ex. Chlorhexidine.
3- Third generation: as compared to chlorhexidine they don’t exhibit good retentive
properties ex. Delmopinol.
Composition of mouth rinse:
1-Alcohol is used as a solvent.
2- Surface active agents: to facilitate cleaning.
3- Water.
4- Sweeting agent.
5- Coloring agent.
6- Flavoring agent.
7- Active agent.
Side effects of mouth rinses:
1- Mouth rinses that contain high level of alcohol may produce burning sensation in
cheeks, teeth and gum.
2- Rinses with more concentrated mouth rinses may cause ulcer, root sensitivity, stains,
changes in taste sensation.
3- Mouth rinses that contain fluoride compounds if swallowed may lead to fluorosis.
The most common mouth rinses used are:
1-Chlorhexidine: it is the most effective chemical antiplaque and antigingivitis
agent.
Mode of action: it has broad spectrum bacterial activity against Gram +ve and Gram ve bacteria. It is used in the form of chlorhexidine gluconate. The positively charged
chlorhexidine binds to bacterial cell walls and to various oral surfaces including the
hydroxyl apatite group of tooth enamel.
It is slowly dissolved from these sites to exert prolong bacterial effect, and had
bacteriostatic effect for several hours, interact with bacteria damaging
permeability barriers and precipitate cytoplasm, the frequency of application
should be twice daily of 0.2% (10 ml) for 1 min. this will decrease bacterial count
85%-95% in those with gingivitis and periodontitis with pocket not exceed 3 mm.,
but those with
pocket over 3 mm. chlorhexidine has no
effect.
Side effects of chlorhexidine mouth rinses:
1- Unpleasant taste.
2- Brown discoloration of teeth and fillings.
3- Disturbances in taste sensation may last for several hours.
Clinical application:
1- After periodontal surgery.
2- Long term plaque control in handicapped patients.
2- Phenolic compounds:
An average 35% reduction of plaque and gingivitis has been documented, these
include:
1- Listerine: it is less effective than of chlorhexidine. Reported side effects include
1- burning sensation, 2- bitter taste, 3- staining of teeth.
2- Triclosan: it has recently included in mouth rinses and tooth pastes. It has broadspectrum activity against Gram +ve and Gram -ve bacteria.
3-Antibiotics: antibiotics such as vancomycin, erythromycin and kanamycin have
been used as agent for plaque control, however due to potential problems of
bacterial resistance and hypersensitivity reactions, the use of these agents have
reduced.
6- All of these are considered as side effects of Listerine mouth wash except
a. burning sensation
b. ulceration
c. staining of teeth
d. bitter taste
Note: one degree for each answer
Check your answers in key answer page at the end of module
If you got:
- 5 or more so congratulation your performance go on studying the second module.
- less than 5, go back and study the first module or any part of it then
Lecture 30
Review for all previous lectures