BIOFILM IN ENDODONTICS
DR. LAXMIPRIYA C H
POSTGRADUATE STUDENT
DEPARTMENT OF CONSERVATIVE DENTISTRY
CONTENTS
• Introduction
• Definition of biofilm
• Criteria for biofilm
• Composition of biofilm
• Characteristics of biofilm
• Development of biofilm
• Stages of biofilm formation
• Resistance of microbes in biofilm to antimicrobials
• Endodontic biofilms
• Types of Endodontic biofilms
-intracanal biofilm
-Extraradicular biofim
-Periapical biofilm
-Biomaterial centered infection
• Methods to study biofilm
• Current and future therapeutic strategies against
endodontic biofilm
• Summary
• Conclusion
• References
INTRODUCTION
 APICAL PERIODONTITIS - biofilm-mediated infection
 Biofilm
- protects bacteria from host defenses
-
increase their resistance to intracanal disinfecting protocols
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
 Understanding the virulence of these endodontic
microbiota within biofilm
essential for the development of novel
therapeutic procedures for intracanal disinfection
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
Disruption
of biofilms
Killing of
bacteria in
biofilm
Necessary to effectively treat APICAL PERIODONTITIS
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
Definition
 Biofilm can be defined as a sessile multicellular microbial
community characterized by cells that are firmly attached to a
surface and enmeshed in a self-produced matrix of extracellular
polymeric substance (EPS), usually a polysaccharide
Cohen 11th edition
Biofilm is a mode of microbial growth where dynamic
communities of interacting sessile cells are irreversibly
attached to a solid substratum, as well as each other,
and are embedded in a self-made matrix of
extracellular polymeric substances (EPS)
Ingle’s 6th edition
 A microbial biofilm is considered a community that meets
the following four basic criteria – caldwell et al
The microorganisms living in the community
 must possess the abilities to self-organize - autopoiesis
 resist environmental perturbations - homeostasis
Jhajharia, et al. Biofilm in endodontics: A review Journal of International Society of Preventive and
Community Dentistry January-February 2015, Vol. 5, No. 1
 must be more effective in association than in isolation synergy
 respond to environmental changes as a unit rather than
single individuals - communality
Jhajharia, et al. Biofilm in endodontics: A review Journal of International Society of Preventive and
Community Dentistry January-February 2015, Vol. 5, No. 1
COMPOSITION OF BIOFILM
 A fully developed biofilm - heterogeneous arrangement
of microbial cells on a solid surface
 Biofilm consists of
Matrix material
85% volume
15% cells
T. Akshay Satwik, Pradeep Solite, R. Sarah Sathiyawathie. Role of biofilms in endodontics. Drug Invention
Today .Vol 11 (4) 2019
 Surface adherent surface cells -main component of the
biofilm
 Water channels - primitive circulatory system
T. Akshay Satwik, Pradeep Solite, R. Sarah Sathiyawathie. Role of biofilms in endodontics. Drug Invention
Today .Vol 11 (4) 2019
 Typically, a viable, fully hydrated biofilm appears as ‘‘tower’’
or ‘‘mushroom’’shaped structures adherent to substrate
 The overall shape of a biofilm structure is determined by
the shear forces generated by the flushing of fluid media.
Ingle’s Endodontics 6th edition
 As biofilm get matured - structure and composition -modified
according to the environmental conditions
 Biofilm mediated mineralization occurs when the metal ions
including Ca2+, Mg2+, and Fe3+ readily bind and precipitate
within an ionic biofilm under a favorable environment
T. Akshay Satwik, Pradeep Solite, R. Sarah Sathiyawathie. Role of biofilms in endodontics. Drug Invention
Today .Vol 11 (4) 2019
Schematic representation of the structure of a mature biofilm
Ingle’s Endodontics 6th edition
CHARACTERISTICS OF BIOFILM
Bacteria
in a biofilm state
Distinct capacity to survive tough growth and
environmental conditions
Ingle’s Endodontics 6th edition
This unique capacity of bacteria in a biofilm state is
due to the following features:
 biofilm structure protects the residing bacteria from
environmental threats
 structure of biofilm permits trapping of nutrients and
metabolic cooperativity between resident cells of same species
and/or different species;
Ingle’s Endodontics 6th edition
 biofilm -display organized internal compartmentalization,
which allows bacterial species with different growth
requirements to survive in each compartment
 Bacterial cells in a biofilm community may communicate
and exchange genetic materials to acquire new traits.
Ingle’s Endodontics 6th edition
PROTECTION OF BIOFILM BACTERIA FROM
ENVIRONMENTAL THREATS
 Bacteria are capable of producing polysaccharides,
either as cell surface structures (capsule) or as
extracellular excretions (EPS)
 EPS covers biofilm communities and creates a microniche
favorable for the long-term survival and functioning of the
bacterial communities
Ingle’s Endodontics 6th edition
NUTRIENT TRAPPING AND ESTABLISHMENT OF METABOLIC
COOPERATIVITY IN A BIOFILM
 Highly permeable and interconnected water channelsmaterial exchange.
water channel
 connects the outer fluid medium with the
interior of the biofilm
 ensure nutrient availability to microbial
communities deep inside the biofilm structure
Ingle’s Endodontics 6th edition
ORGANIZED INTERNAL COMPARTMENTALIZATION
IN BIOFILM
 A mature biofilm- displays gradients in the distribution of
nutrients, pH, oxygen, metabolic products, and signaling
molecules within the biofilm
create different microniche that can accommodate
diverse bacterial species within a biofilm.
Ingle’s Endodontics 6th edition
Schematic diagram representing cell–cell communication in a biofilm. Some bacteria can
produce chemical signals (green) and other bacteria from the same species or from different
species or strain can respond to them (red)
Ingle’s Endodontics 6th edition
BACTERIAL CELLS RESIDING IN A BIOFILM COMMUNICATE,
EXCHANGE GENETIC MATERIALS, AND ACQUIRE
NEW TRAITS
 Communications between bacterial cells residing in a biofilm is
attained through signaling molecules
Process called QUORUM SENSING
Ingle’s Endodontics 6th edition
Schematic diagram showing quorum sensing in biofilm
bacteria
Ingle’s Endodontics 6th edition
DEVELOPMENT OF BIOFILM
 3 major components involved in biofilm formation
Bacterial
cells
solid
surface
Fluid
medium
Ingle’s Endodontics 6th edition
Ingle’s Endodontics 6th edition
Stages of biofilm formation
Gunnel svensater & gunnar bergenholtz. Biofilms in endodontic infections. Endodontic topics
2004, 9, 27–36
Ingle’s Endodontics 6th edition
Schematic diagram showing co-aggregation and co-adhesion
between different bacterial cells forming biofilm.
Ingle’s Endodontics 6th edition
 Detachment – important role in shaping the morphological
characteristics
 It is also an “active dispersal mechanism” or “seeding dispersal”
detached cells form resistance traits
source of persistent infections
T. Akshay Satwik, Pradeep Solite, R. Sarah Sathiyawathie. Role of biofilms in endodontics. Drug Invention
Today .Vol 11 (4) 2019
Erosion
Sloughing
 continual detachment of single cell and
small portions of biofilm
 a process of rapid, massive loss of
biofilm
T. Akshay Satwik, Pradeep Solite, R. Sarah Sathiyawathie. Role of biofilms in endodontics. Drug Invention
Today .Vol 11 (4) 2019
Resistance of Microbes in Biofilm to Antimicrobials
The mechanisms responsible include:
 resistance associated with the extracellular polymeric matrix
 resistance associated with growth rate and nutrient availability
 resistance associated with the adoption of resistance phenotype
Ingle’s Endodontics 6th edition
Schematic diagram showing factors contributing to resistance against antimicrobial
agents.
Ingle’s Endodontics 6th edition
Endodontic biofilms
 Endodontic microbiota -less diverse -oral microbiota.
 Progression of infection
alters the nutritional and environmental status -root canal
more anaerobic with depleted nutritional levels.
Lakshmi Narayanan and Vaishnavi: Endodontic microbiology . Journal of Conservative Dentistry OctDec 2010. Vol 13 ,Issue 4
 Endodontic infection
Primary
Secondary
 PRIMARY ENDODONTIC INFECTIONS - polymicrobial
 They are predominantly Bacteroides, Prophyromonas, Prevotella,
Fusobacterium, Treponema, Peptostreptococcos, Eubacterium &
Camphylobacter species.
Prasanna Neelakantan ,Monica Romero , Jorge Vera , Umer Daood , Asad U. Khan , Aixin Yan ,Gary Shun
Pan Cheung . Biofilms in Endodontics—Current Status and Future Directions. Int. J. Mol. Sci. 2017
 SECONDARY INFECTIONS - microbial flora - able to
survive harsh conditions
 Studies have shown the prevalence of certain species in teeth
with post-treatment infection
Enterococci, Streptococci, Lactobacilli, Actinomyces & fungi
 In particular, a high proportion of Enterococcus fecalis in
cases with persistent apical periodontitis
Prasanna Neelakantan ,Monica Romero , Jorge Vera , Umer Daood , Asad U. Khan , Aixin Yan ,Gary Shun
Pan Cheung . Biofilms in Endodontics—Current Status and Future Directions. Int. J. Mol. Sci. 2017
 Complete disinfection of root canal is very difficult to achieve
because of persistent microbes in anatomical complexities and
apical portion of root canal
 Biofilm - survives unfavorable environmental and
nutritional condition - the root canal environment will
favor biofilm formation
Lakshmi Narayanan and Vaishnavi: Endodontic microbiology . Journal of Conservative Dentistry OctDec 2010. Vol 13 ,Issue 4
Biofilm mode of bacterial growth offers other advantages such as
 resistance to antimicrobial agents
 increase in the local concentration of nutrients
 opportunity for genetic material exchange
Ingle’s Endodontics 6th edition
 ability to communicate between bacterial populations
of same and/or different species
 produce growth factors across species boundaries.
Ingle’s Endodontics 6th edition
Endodontic bacterial biofilms can be categorized as
Intracanal biofilms
Extraradicular biofilms
Periapical biofilms
Biomaterial-centered
infections
Ingle’s Endodontics 6th edition
Intracanal biofilms
 Intracanal microbial biofilms are microbial biofilms formed on
the root canal dentine of an endodontically infected tooth
 A detailed description on the intracanal bacterial biofilm was
documented by Nair in 1987
Ingle’s Endodontics 6th edition
Nair reported that despite instrumentation, irrigation, and
obturation for single-visit treatment of mandibular first molars
with primary apical periodontitis,
microorganisms persisted within biofilms in
untouched areas of canals and isthmuses
intracanal biofilms.
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
Intracanal biofilm
 Intracanal microbiota in an endodontically infected teeth existed
as both loose collection and biofilm structures, made up of cocci,
rods, and filamentous bacteria
 Monolayer and/or multilayered bacterial biofilms were
found to adhere to the dentinal wall of the root canal
 The extracellular matrix material of bacterial origin -interspersed
with the cell aggregates in the biofilm.
Ingle’s Endodontics 6th edition
 Morphologically distinct types of bacteria - observed in these
biofilms
 Bacterial microcolonies - coaggregation of single morphological
type and/or several morphological types of bacteria
 In a multispecies biofilm - proportion and number of different
bacterial species varied according to the stage of maturation
Ingle’s Endodontics 6th edition
 Intracanal biofilms displayed characteristic bacteria–
dentine wall relationship and distinct patterns in the
organization of microbes in the biofilm
 Studies have established the ability of E.faecalis to
resist starvation and develop biofilms under different
environmental and nutrient conditions
Ingle’s Endodontics 6th edition
 Sen et al investigated the root canal walls of
infected teeth by SEM
Bacteria formed dense colonies on the canal
walls as well as in intra- and inter-tubular dentin
 In addition to bacteria, fungi were capable of forming
dense, but separate colonies all over the root canal walls
Mohammadi Z, Palazzi F, Giardino L , Shalavi S.Microbial Biofilms in Endodontic Infections: An
Update Review Biomed J 2013;36:59-70
 George et al - evaluated the ability of E. faecalis to
develop biofilm
Aerobic
Anaerobic
Nutrient-rich
Nutrient-deprive
d conditions
Mohammadi Z, Palazzi F, Giardino L , Shalavi S.Microbial Biofilms in Endodontic Infections: An
Update Review Biomed J 2013;36:59-70
Stage 1
E. faecalis cells adhered and formed microcolonies
on the root canal dentine surface
Stage 2
They induced bacterial-mediated dissolution
of the mineral fraction from the dentine substrate.
Stage 3
This localized increase in the calcium and phosphate
ions will promote mineralization or calcification
of the E. faecalis biofilm
Ingle’s Endodontics 6th edition
 The mature biofilm structure formed after 6 weeks of
incubation showed signs of mineralization
 Obvious signs of dentine surface degradation under
nutrient-deprived environment
Ingle’s Endodontics 6th edition
 Degradation of dentine substrate - consequence of the
interaction of bacteria and their metabolic products on
dentine
 Inherent capacity- E. faecalis - may contribute to its
persistence in endodontically treated teeth.
Ingle’s Endodontics 6th edition
Scanning electron microscopy images showing the morphology of Enterococcus faecalis
biofilms formed on root canal dentine under A, nutrient-deprived condition after 1
week, B, nutrient-deprived condition after 4 weeks, C, nutrient-rich condition after 1
week, and D, nutrient-rich condition after 4 weeks.
Ingle’s Endodontics 6th edition
 Investigations -biting force-induced retrograde fluid movement
into the apical portion of the root canal
 Cyclic influx of ion-rich tissue fluid into the apical portion of the
root canal can promote persistence of bacteria as biofilms and
their mineralization
 while internal resorption can be a consequence of bacterialmediated substrate dissolution.
Ingle’s Endodontics 6th edition
EXTRARADICULAR MICROBIAL BIOFILMS
 Extraradicular microbial biofilms root surface biofilms are microbial
biofilms formed on the root (cementum) surface adjacent to the
root apex of endodontically infected teeth
 Extraradicular biofilms Asymptomatic
Periapical
periodontitis
chronic apical
abscesses
associated with
sinus tracts.
Ingle’s Endodontics 6th edition
 Tronstad et al - examined 10 root tips removed during surgical
treatment of root-filled teeth with post-treatment disease
 Mature bacterial biofilms were found in many areas of the
apical root surfaces in all clinical specimens
 They observed bacterial biofilms in the areas of the root surfaces
between fibers and cells and in crypts and holes
Mohammadi Z, Palazzi F, Giardino L , Shalavi S.Microbial Biofilms in Endodontic Infections: An
Update Review Biomed J 2013;36:59-70
 The biofilm contained varying degrees of extracellular matrix
materials (glycocalyx)
 The root surface biofilms were mostly multispecies
in nature
Mohammadi Z, Palazzi F, Giardino L , Shalavi S.Microbial Biofilms in Endodontic Infections: An
Update Review Biomed J 2013;36:59-70
 The extraradicular biofilm structures were dominated by
cocci and short rods, with cocci attached to the tooth
substrate
 Filamentous and fibrillar forms were also observed in the
biofilm
Mohammadi Z, Palazzi F, Giardino L , Shalavi S.Microbial Biofilms in Endodontic Infections: An
Update Review Biomed J 2013;36:59-70
 A smooth, structureless biofilm -extracellular matrix
material with embedded bacterial cells was noticed to coat
the apex of the root tip adjacent to the apical foramen
 Ricucci et al - presence of calculus-like deposit on
the root apex of teeth extracted due to post-treatment
periapical periodontitis.
Ingle’s Endodontics 6th edition
 Harn et al - calculus-like deposits on apical root surface of
tooth presented with lesion refractory to conventional
root canal treatment
 These calcified biofilms were associated with periapical
inflammation and delayed periapical healing in spite of
adequate orthograde root canal treatment
Ingle’s Endodontics 6th edition
Extraradicular microbial biofilm formed on the root surface. It is A,
multispecies or B, smooth and structureless in nature
Ingle’s Endodontics 6th edition
PERIAPICAL MICROBIAL BIOFILMS
 Periapical microbial biofilms are isolated biofilms found in
the periapical region of an endodonticallyinfected teeth.
 Periapical biofilms may or may not be dependent on the
root canal.
Ingle’s Endodontics 6th edition
 The microbiota in the majority of teeth associated with apical
periodontitis
restricted to the root canal
most of the microbial species that infect the root canal
are opportunistic pathogens
do not have the ability to survive host
defense mechanism in the periapical tissues
Ingle’s Endodontics 6th edition
Actinomyces
P.propionicum
Asymptomatic periapical lesions refractory
to endodontic treatment
Ability to overcome host defense mechanisms, thrive
in the inflamed periapical tissue - induce a periapical infection
Ingle’s Endodontics 6th edition
 Actinomyces species - grow in microscopic or
macroscopic aggregates -3 to 4mm
 Sulfur granules - yellow granular appearance.
 Ray fungus
 Aggregation of cells -biofilm - that differentiate,
communicate, cooperate, and deploy collective defense against
biological antimicrobials
Ingle’s Endodontics 6th edition
 Periapical region - ‘‘patrolled’’ by PMNs &
macrophages-phagocytose incoming planktonic bacteria
easily
 Unable to engulf bacteria in matrix-enclosed biofilm
structure
Ingle’s Endodontics 6th edition
 Sunde et al - reported the incidence of ‘‘sulfur
granules’’ in nine refractory periapical lesions and
found bacteria in seven.
 A. israelii, A. viscosus, A. naeslundii, Actinomyces
meyeri were identified in five granules
Ingle’s Endodontics 6th edition
 Many of the ‘‘sulfur granules’’ were calcified
 Source for mineralization - the inflammatory exudate and/or
the activity of the periapical bacteria
 Lysis of adherent bacterial cells in a biofilm would induce
cell calcification
Mohammadi Z, Palazzi F, Giardino L , Shalavi S.Microbial Biofilms in Endodontic Infections: An
Update Review Biomed J 2013;36:59-70
BIOMATERIAL-CENTERED INFECTION
 Biomaterial-centred infection (BCI) is caused when bacteria
adheres to an artificial biomaterial surface and forms biofilm
structures
Ingle’s Endodontics 6th edition
 Presence of biomaterials in close proximity to the host
immune system can increase the susceptibility to BCI
 BCI is one of the major complications associated with
prosthesis and/or implant-related infections
Ingle’s Endodontics 6th edition
 Because biofilms - extremely resistant to host defense
mechanisms and antibiotic treatments
BCI are rarely resolved - often the
only solution to an infected biomaterial such as
Implant is its surgical removal
Ingle’s Endodontics 6th edition
 BCI usually reveals opportunistic invasion by
nosocomial Organisms
 Staphylococcus, S. aureus, enterococci, streptococci, P.
aeruginosa, and fungi - commonly isolated from infected
biomaterial surfaces
Mohammadi Z, Palazzi F, Giardino L , Shalavi S.Microbial Biofilms in Endodontic Infections: An
Update Review Biomed J 2013;36:59-70
Bacterial adherence to a biomaterial surface - three phases
phase 1
transport of bacteria to biomaterial surface
phase 2
initial, non-specific adhesion phase
Phase 3
specific adhesion phase.
Ingle’s Endodontics 6th edition
Bacterial strains that do not produce EPS
Less adherent & less pathogenic
Rapidly destroyed by the immune system.
These features highlight the need to prevent bacterial adherence
and biofilm formation to prevent BCI
Ingle’s Endodontics 6th edition
In endodontics - biomaterial-centered biofilms would
form on root canal obturating materials
Intraradicular
Extraradicular
Obturating material is within the root
canal space or has it extruded beyond the root apex
Ingle’s Endodontics 6th edition
 A study investigated the initial biofilm-forming ability of
root canal isolates such as E. faecalis, S. sanguinis, S.
intermedius,S. pyogenes, S. aureus, F. nucleatum, P.
acnes, P. gingivalis, and P. intermedia on gutta-percha
points in vitro
Ingle’s Endodontics 6th edition
 E. faecalis & S. sanguinis biofilms - significantly thicker than
those of S. intermedius, S. pyogenes, and S. aureus
 F. nucleatum, P. acnes, P. gingivalis, and P. intermedia did not
form biofilms on gutta-percha
 The findings suggested that Gram-positive facultative
anaerobes have the ability to colonize and form extracellular
matrices on gutta-percha points
Ingle’s Endodontics 6th edition
Scanning electron microscopy image of A, microbial biofilm formed on
extruded gutta-percha point from a clinical sample and B, E. faecalis biofilm
formed on gutta-percha in vitro.
Ingle’s Endodontics 6th edition
METHODS TO STUDY BIOFILM
Atomic force
microscopy (afm)
Nuclear magnetic
resonance (NMR)
Green fluorescent
protein (GFP)
tagging
Fourier transform
infrared (FTIR)
spectroscopy
SEM & TEM
FISH
confocal laser
scanning
microscopy (CLSM)
flow
cytometry
Jhajharia, et al. Biofilm in endodontics: A review Journal of International Society of Preventive and
Community Dentistry January-February 2015, Vol. 5, No. 1
CURRENT AND FUTURE THERAPEUTIC STRATEGIES
AGAINST ENDODONTIC BIOFILM
 Irrigants for biofilm eradication
 Intracanal medicament for biofilm eradication
 Laser-assisted eradication of biofilms
 Effect of Lactobacillus plantarum LTA
 Effect of nanoparticles, photodynamic therapy, ozone,
and enzymes
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
Irrigants for biofilm eradication
Sodium
hypochlorite
(NaOCl)
E. FECALIS
lipoteichoic
acid (LTA) with
NaOCl
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
Chlorhexidine
(CHX)
digluconate
CHX cannot be used as main root canal irrigant because it does
not have tissue solvent activity
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
EDTA
 In addition to smear layer removal, EDTA irrigation can be
beneficial in disruption of biofilm
 Ozdemir et al - demonstrated that combination of
EDTA and NaOCl significantly reduced the amount of
intracanal biofilm in both young and old aged biofilms
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
 Soares et al
reported that the NaOCl-EDTA alternating irrigation was
a promising regimen for elimination of intracanal
E. faecalis biofilms
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
Irrigant Activation
Mechanisms
 Complexity of the root canal anatomy and tenacious nature
of the biofilms dictate that simple delivery of antimicrobial
agents is not sufficient for disinfection of root canal systems.
 Irrigation activation -satisfactorily deliver these antimicrobial
agents into the complex anatomy,
interfere with the adhesive mechanisms by inducing
shear stress and disrupt the biofilms
Prasanna Neelakantan ,Monica Romero , Jorge Vera , Umer Daood , Asad U. Khan , Aixin Yan
,Gary Shun Pan Cheung . Biofilms in Endodontics—Current Status and Future Directions. Int. J.
Mol. Sci. 2017
RINSENDO
GENTLE WAVE
ENDOVAC
PIPS
ENDOACTIVATOR
VATEA SYSTEM
Intracanal medicament for biofilm eradication
Calcium
hydroxide
 Release of aqueous hydroxyl ions to raise pH so
that microbes cannot survive
 Elevated pH alters membrane integrity
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
 Damage in the lipid moieties of bacterial virulence factors
- unique detoxification mechanism of CH
 E. faecalis - resistant to CH- proton pump for and
inhibitory dentin buffering effect
 CH can also inactivate lipopolysaccharide (LPS) in gram
negative bacteria, via hydrolysis of fatty acid in the lipid
moiety
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
Chlorhexidine
 Positively charged CHX molecules interact with negatively
charged membrane phospholipids
 CHX - superior antifungal activity compared to CH, up to 400
μm depth dentinal tubules
 Provides substantive antimicrobial activity
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
Human beta
defensins
 Cationic antimicrobial peptides that are critical host
defense against microbes
 They bind to the negatively charged molecules on bacterial
surface and disrupt bacterial membranes
 HBD-3 is strongly inhibitory, whereas HBD-1, -2, and -4 have
weak antimicrobial effects on E. faecalis
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
 HBD-1, -2, -3, and -4 are produced in normal and inflamed dental
pulp
 They may protect the pulp from inflammation induced by LTA of
gram-positive bacteria and LPS of gram-negative bacteria
 Synthetic HBD-3 consisting of the C terminal 15 amino acids
(HBD3-C15) was reported to be effective for disinfecting
endodontic biofilm including C. albicans
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
Triple antibiotic
paste
 Triple antibiotic paste (TAP) - a mixture of metronidazole,
ciprofloxacin & minocycline
 It is effective on infected dentin, intracanal biofilms, and the
majority of endodontic pathogens
 But its toxicity to residual undifferentiated cells and periapical
tissues limits its application in REP
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
Laser-assisted eradication of biofilms
 A low power laser directed at the access cavity combined with
a photosensitizing agent was bactericidal on S.intermedius
biofilms in root canals, but less effective than NaOCl (3%)
irrigation
 Er:YAG laser was effective on apical root apex biofilms in vitro
 However, endodontic pathogens in biofilms were difficult to
eradicate despite direct laser exposure ex vivo
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
Effect of Lactobacillus plantarum LTA
 L. plantarum - probiotic - antiinflammatory & anti-biofilm effect
 LTA inhibit biofilm formation by :
controlling gene
expression
Quorum sensing
inhibiting EPS
production
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
 LTA also disrupted preformed biofilm of E. faecalis and S. aureus L.
plantarum
 LTA reduced not only mono-species biofilm, but also multispecies biofilm consisting of A. naeslundii,E. faecalis, Lactobacillus
salivarius, and S. mutans
 Cooperatively enhanced disruption of oral multispecies biofilm
when combined with CH and CHX intracanal medicaments
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
Effect of nanoparticles, photodynamic therapy, ozone,
and enzymes
Nanoparticles
 Synthesized from powders of silver, copper oxide, and zinc oxide broad antimicrobial applications
 Generate reactive oxygen species (ROS) -cytotoxic for bacteria
 Higher surface area - greater potential for bacterial interactions
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
 Numerous positively charged nanoparticles accumulate on
negatively charged bacterial cell membranes, which increase
permeability to destroy cells
 Additionally, cationic nanoparticles adhere to negatively
charged dentin surface to prevent biofilm formation
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
Photodynamic
therapy (PDT)
 PDT- photosensitizer is preferentially localized in tissue activated by
appropriate wavelength light to generate reactive oxygen that
kill bacteria
 Penetration of the activating light & photosensitizer may be
limited within root canal structures.
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
 When microorganisms were sensitized with methylene blue all
bacterial species except E. faecalis (53% killing) were destroyed
 When this was followed by the addition of red light with an
optical fiber, almost all (97%) E. faecalis biofilm bacteria in root
canals were eliminated
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
Ozone
 Ozone gas (HealOzone, KaVo, Biberach, Germany) has yielded
inconsistent result in destroying endodontic pathogens
 These inconsistencies may have been due to variation
in concentration and duration of application
 There is conflicting evidence on its antimicrobial efficacy and
reduced effects on sessile versus planktonic bacteria
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
Enzymes
 Natural plant extracts such as polyphenols, Morinda citrifolia,
and turmeric
 Enzymes - dispersin B and proteinase K, have been proposed
for treating biofilm medicated infections.
 But studies are needed to demonstrate their efficacy.
Yoo,Yeon-Jee et al. Endodontic biofilms: contemporary and future treatment options. Restorative
Dentistry & Endodontics(2019), 44 (1)
SUMMARY
• Definition
• Composition of biofilm
• Characteristics of biofilm
• Development of biofilm
• Stages of biofilm formation
• Resistance of microbes in biofilm to
antimicrobials
 Endodontic biofilms
 Types of Endodontic biofilms
-intracanal biofilm
-Extraradicular biofim
-Periapical biofilm
-Biomaterial centered infection
 Various methods to study biofilms
 Therapeutic strategies against endodontic biofilm
CONCLUSION
 Application of the biofilm concept to endodontics will play a
vital role in helping us to understand, not only the pathogenic
potential of the root canal microbiota but also the basis for
new approaches for disinfection.
 Microorganisms adaptation under disease conditions and their
organization in root canals are important issues - to obtain a
clear understanding of how the root canal bacteria resist
endodontic treatment measures
 Recent developments in biocompatible intracanal medicaments
including synthetic HBDs and L. plantarum LTA could open up
new avenues as an ideal therapeutic agent to eradicate
endodontic biofilm.
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