Care of Dental Restorations
Chapter 43
Dental Amalgam Restorations
• Margination- Process of removing excess
restorative material and applying finishing
techniques to re-establish a smooth, welladapted cavosurface margin. The resultant
junction should conform in shape and normal
anatomic characteristics.
• Finishing-process that involves removing
marginal irregularities, defining anatomic
contours, and smoothing away surface
roughness of a restoration.
Dental Amalgam Restorations
• Polishing- process carried out after
placement of a restoration to remove
minute scratches from the surface of a
restoration and obtain a smooth, shiny
luster. Also applied after other refinishing
techniques to produce an unscratched
homogeneous surface. Uses abrasive
agents to remove roughness, eliminate
pits or grooves, and make the surface
more resistant to bacterial accumulation.
Characteristics of an acceptable
finished and polished restoration.
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Smooth anatomic contours
Contact areas intact with normal form
Embrasures spaced correctly
Refined margins
Smooth resistant surfaces
Functional effectiveness
Acceptable appearance
No biofilm-retaining irregularities
Restored health of the gingival tissues
Indications for use of Margination
• Excess interproximal material (i.e.,
overhang, such as a Class II amalgam
restoration) which could cause:
– Gingival tissues appearing inflamed in the
area
– Localized vertical bone loss radiographically
or when probing
– Dental floss often fraying
Benefits of Margination
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Removes excess amalgam
Facilitates plaque control
Promotes healthier periodontal tissues
Recreates functional anatomy to the
restored tooth surface
Instruments that could be used for
Margination
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Finishing knives
Files
Scalers, curettes, spoon excavators
Cleoid-discoid carvers
Ultrasonic scaler
Finishing discs
Finishing polishing strips
Finishing strips
• Description: thin, flexible strip of metal
(lightening strip), linen abrasive strip or
plastic impregnated with abrasive particles
on one side.
• Available in varying grits,
– Extra fine to course
Technique to remove a large
overhang
• Assess the overhang
– Use an explorer
– Assess the condition of the adjacent gingival
tissue to determine ease of access to
overhang.
– Select instruments based on size of overhang
and ease of subgingival access.
Technique to remove a large
overhang
• Initial margination
– Use a sharp amalgam or appropriate ultrasonic scaler
insert
– Secure fulcrum
– Angulate the blade/insert so only a small portion of
the amalgam will be removed
– Use short, overlapping, shaving strokes
– Avoid removing too much of the overhang
– Smooth with a curette
– Finish with an abrasive strip
Polishing an amalgam restoration
• Use wet polishing agents
• Use low speed hand-piece with light
intermittent strokes
• Avoid cementum
• Do not over-polish
Rubber cups and points
• Amalgam polishing kit
– Brown and green rubber cups and points
have abraisve incorporated in them
– Points are used for occlusal
– Cups are used for proximal surfaces
– Use in this order:
• Brown
• Green
Sterilize after each use
Mounted brushes
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Soften brushes in warm water
Use a fine pumice
Apply agent over the area
Use a slow to moderate speed
Use dental tape to apply to proximal surfaces
Use course to fine abrasive to acquire finish
desired
• Rinse well
Tin oxide
• Use as final polish
-apply with light intermittent strokes
Rinse and evaluate
Esthetic restorations
• Composite resins
– Class I and II posterior direct restorations
– Class III, IV, and V anterior direct restorations
– Veneeri for teeth that have been intrinsically
stained
– Filling of diastemas
– Improve size or contour of small or misshaped teeth
– Pit and fissure sealants
Characteristics of a composite
restoration
• Softer to an explorer than enamel or
porcelain
• Esthetic, tooth colored, but may stain
• Highly polishable
• Must individualize which polishing agent to
use.
Polishing a composite restoration
• Indications for polishing:
– Surface roughness
– Surface discoloration
– Flash or overhang
– Over-filled restorations
Polishing a composite restoration
• Contraindications include:
– Open margins
– Fractured restorations
– Under-contoured proximal contacts
– Large overhangs
– Recurrent caries
******
• FYI
– The use of a plastic matrix strip before
polymerization minimizes the amount of
finishing required to produce a smooth,
regular contoured surface.
Contraindications for composite
restorations
• Use of acidulated phosphate or stannous
fluoride
• –may cause alteration of the filler particles
• -Discoloration of the resin
• -avoid mouthrinses containing alcohol
– Alcohol may act as a soolvent for the BISGMA resin resulting in softening of the
material—making it rougher and stain easier.
Polishing a composite restoration
• Use rubber points (containing abrasives)
on a slow-speed handpiece.
• Also, can use with aluminum oxide or
diamond pastes that contain particles as
small as 1 um in diameter to create
smooth, reflective surfaces.
Microfilled composite resins
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Composed of very fine silica filler
Polish very smooth
Possess excellent polishing qualities
Higher luster than hybrid composite resins
Microfilled composite resins
• Areas used:
– Anterior esthetic restorations
– Diastema closures
– Hand-sculpted composite veneers
– Class III and V restorations
Microfilled composite resins
• Easy to regain surface luster
• High surface shine using rubber polishing
cups, wheels, and points
• Easy to ditch or scratch upon margination
• Chips can be modified and stains can be
removed with a sequence of finishing
discs and strips.
Hybrid Composite resins
• A mixture of a mix of glass and silica with
large, different-sized filler particles.
• They can be used where strength and
wear resistance are more important than
surface luster.
Hybrid Composite resins
• Class IV anterior restorations
• Incisal edges of anterior teeth
• Class I or II posterior restorations where
there is a moderate stress chewing load.
Hybrid Composite resins
• More difficult to achieve and maintain a
high luster polish
• Best strength of all resin categories
• Poishable using a diamond-impregnated
polisher
• Does not polish as smoothly or with as
much shine as the microfill composite
resins.
Compomer
• Is a direct esthetic restorative material that
is a combination of glass ionomer and
composite.
Compomer
• Used in Class I, II, III, and V restorations in
low stress-bearing areas of patients with
moderate risk for dental caries.
• Buildups or cores for cast crowns
• Esthetic repair for fractured or chipped
porcelain restorations.
Compomer
• Characteristics
– Smoother surface than glass ionomer, but not
as smooth as composite resin materials
– Best translucency an any of the direct esthetic
restorative materials
– Releases fluoride similar to glass ionomers
– Less wear resistant than composites
– Good handling characteristics.
Glass ionomer resins
• Composed of a polyacrlic matrix filled with
aluminosilicate particles.
• **The benefit of using glass ionomer
restorative material is the release of
fluoride to reduce dental caries.
Glass ionomer resins
• Uses:
– Cements
– Low stress-bearing restorations
– Limited use as Class I and II restorations in
the primary dentition
– Class I, II, and V restorations on a high caries
risk patient where esthetics are not critical
Glass ionomer resins
• Characteristics
– Cannot be polishned to the same smoothness
as composite resin
– Minimal shine
– Brittle
– Higher incidence of fracture and wear
– More opaque—less desirable than other
composite resin materials
Porcelain
• Mostly are completed in the laboratory
prior to cementation.
• Cerec
• Longest lasting cosmetic restoration
material
• When maintained the porcelain restoration
can last for many years---if it is not—the
restoration can become rough.
Porcelain
• If the porcelain restorative material
becomes rough:
– Can increase wear of the opposing dentition
– Increase the susceptibility to stain and dental
caries.
– Periodontal inflammation can occur is the
gingival margins are not adequately polished.
Porcelain
• High fusing material is used for detnure
teeth
• Medium fusing material is used for anterior
porcelain jacket crowns, ceramic
restorations, inlays, onlays and crowns.
• Low fusing material is used in porcelainfused- to- metal crowns.
Porcelain
• Characteristics
– Mimics tooth color
– More esthetic appearance than composite
resins
– Retains luster
– Subject to fracture
– Staining
Dental hygiene care for porcelain
• Gently debride deposits with curets
• Avoid the use of a sickle, ultrasonic, or
sonic scaler, air polisher, or air abrasive
unit.
• Consider the use of a plastic instrument
instead.
Dental hygiene care for porcelain
• Use a low-speed handpiece
• Special paste for porcelain use
• Moisten a soft, flexible rubber cup or felt
disc or wheel
• Polish for 15-30 seconds
• Dilute the paste with water as the polishing
progresses
How can the DH identify the
restorative material?
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Review patient record
Gather patient information
Use tactile detection with a dental explorer
Use air—esthetic restorations may reveal
a dry, chalky appearance.
Finishing and Polishing Materials
• The intent of polishing is to:
– create a restorations that fit and maintain
occlusal harmony
– to produce a smooth surface
– Less plaque and calculus adherence
– Decrease the potential for the corrosion of
metal restoration material.
Abrasive procedure
• Abrasion is the wearing away or removal
of material by rubbing, cutting, or scraping.
Finishing
• process that involves removing marginal
irregularities, defining anatomic contours,
and smoothing away surface roughness of
a restoration.
Factors that affect finishing
a. Hardness refers to the abrasive’s ability
to cut
b. Size influences the speed of the cut
a. Larger particles abrade a surface more
rapidly.
b. Particles are classified by size in
micrometers(um)
a. Course = 100 um
b. Medium = 10 to 100 um
c. Fine = 0 to 10 um
Pressure applied during finishing
and polishing
1. Of the force, when greater, results in more
rapid removal of the material.
2. When greater, creates increased temperature
and heat.
3. Under higher temperatures can lead to
distortion or physical changes within the
appliance/restoration.
4. With high temperatures may cause discomfort
for the patient because of the transmission of
heat to the pulpal tissues.
Speed of cup/point/brush during
finishing and polishing procedure.
• 1. When faster, results in faster cutting
rates.
• When faster, creates greater
temperatures.
• When faster, creates greater danger of
over-cutting the appliance/restoration.
Types and composition of
abrasives
• Diamond
– Composed of carbon
– Is the hardest substance; is an efficient
abrasive because it does not wear down or
lose sharpness easily
Types and composition of
abrasives
• Carbides
– Include silicon carbide, boron carbide and
tungsten carbide
– Silicon and boron for finishing instruments
typically are supplied as particles pressed
with a binder into disks or wheels for use on a
hand-piece.
Aluminum oxide
• Typically is produced as particles bonded to
paper disks and strips or impregnated into
rubber wheels and points.
• Is the abrasive used for white stones—used for
polishing of porcelain.
• Has fine particles of aluminum oxide and
diamond that can be mixed into a paste to
produce smooth, polished surfaces on many
types of restorations, including acrylics and
composites.
Zirconium silicate
• Is a natural mineral
• Is used as a polishing agent in strips and
disks.
• Often is used in prophylactic pastes.
Tin oxide
• Is used as a polishing agent for metallic
restorations, especially amalgams
• Produces excellent polish of enamel.
Pumice
• Is a natural glass that is rich in silica
• Polishes acrylics and enamel.
Rouge
• Is iron oxide
• Is a powder that can be formed into a
block or cake and used on a rag wheel in
a dental lathe/handpiece to polish gold
alloys.