This document provides an overview of dental plaque, including its:
1) Classification, composition, structure and formation as a biofilm on teeth. Dental plaque is made up of bacteria and an intercellular matrix that accumulates on teeth.
2) Role in dental diseases like caries and periodontitis. The specific bacteria present in plaque influence which diseases may develop.
3) Methods of detection and removal, which are important for oral health maintenance and disease prevention. Effective plaque removal is needed to prevent its buildup and the diseases it can cause.
Dental Plaque
Soft deposits that form the biofilm adhering to the tooth surface or other hard surfaces in the oral cavity, including removable & fixed restorations”
Bowen , 1976
Bacterial aggregations on the teeth or other solid oral structures
Lindhe, 2003
Various Plaque Hypothesis are proposed to prove how plaque becomes pathogenic and cause periodontitis. Helpful in understanding pathogenesis of periodontitis especially how Gingivitis change to Periodontitis. All the details have been added and made in easy language to understand.
Useful for BDS and MDS students
INTRODUCTION
DEFINITION
TYPES OF TRAUMA FROM OCCLUSION
GLICKMAN CONCEPT
WAERHAUG CONCEPT
STAGES OF TISSUE RESPONSE TO INJURY
CLINICAL AND RADIOGRAPHIC FEATURES OF TFO
CLINICAL DIAGNOSIS OF TFO
TFO AND IMPLANTS
TREATMENT OF TFO
CONCLUSION
REFRENCES
Dental Plaque
Soft deposits that form the biofilm adhering to the tooth surface or other hard surfaces in the oral cavity, including removable & fixed restorations”
Bowen , 1976
Bacterial aggregations on the teeth or other solid oral structures
Lindhe, 2003
Various Plaque Hypothesis are proposed to prove how plaque becomes pathogenic and cause periodontitis. Helpful in understanding pathogenesis of periodontitis especially how Gingivitis change to Periodontitis. All the details have been added and made in easy language to understand.
Useful for BDS and MDS students
INTRODUCTION
DEFINITION
TYPES OF TRAUMA FROM OCCLUSION
GLICKMAN CONCEPT
WAERHAUG CONCEPT
STAGES OF TISSUE RESPONSE TO INJURY
CLINICAL AND RADIOGRAPHIC FEATURES OF TFO
CLINICAL DIAGNOSIS OF TFO
TFO AND IMPLANTS
TREATMENT OF TFO
CONCLUSION
REFRENCES
A brief description of all topics to recent advances,SDD, host modulation and diabetes, host modulation in smokers, chemically modified tetracyclines, bisphosphonates
Periodontitis is a complex infection initiated by bacteria –tissue destruction.
Host: the organism from which a parasite obtains its nourishment/ an individual who receives a graft
Modulation: the alteration of function or status of something in response to a stimulus or an altered physical or chemical environment
A brief description of all topics to recent advances,SDD, host modulation and diabetes, host modulation in smokers, chemically modified tetracyclines, bisphosphonates
Periodontitis is a complex infection initiated by bacteria –tissue destruction.
Host: the organism from which a parasite obtains its nourishment/ an individual who receives a graft
Modulation: the alteration of function or status of something in response to a stimulus or an altered physical or chemical environment
Dental plaque biofilm cannot be eliminated permanently.
However, the pathogenic nature of the dental plaque biofilm can be reduced by reducing the bio burden (total microbial load and different pathogenic isolates within that dental plaque biofilm) and maintaining a normal flora with appropriate oral hygiene methods that include daily brushing, flossing and rinsing with antimicrobial mouth rinses.
This can result in the prevention or management of the associated squeal, including the development of periodontal diseases and possibly the impact of periodontal diseases on specific systemic disorders.
explanation of Dental plaque and its composition, pathogenesis, its classification, structure of subgingival plaque, structure of supragingival plaque formation.
tooth associated plaque, implant associated plaque
Calculus (Classification, composition, microbiology etc.pptxDr. Faheem Ahmed
Calculus is a hard deposit that is formed by mineralization of dental plaque on the surfaces of natural teeth and dental prosthesis, generally covered by a layer of unmineralized plaque.
Microbiology of Periodontal diseases with its introduction history, plaque hypothesis, Microbial complexes, Individual pathogens, Advances in microbiological diagnosis,
Control of bacterial biofilms.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
2. Page 2
CONTENTS
1. Introduction
2. Classification of soft deposits
3. Definitions of dental plaque
4. History of dental plaque
5. Classification of dental
plaque
6. Composition & Structure of
dental plaque
7. Formation of dental plaque
8. Dental plaque as a biofilm
9. Physiological properties
10. Microbial specificity of
periodontal disease
11. Detection of dental plaque
12. Conclusion
13. References
PART - I PART - II
3. Page 3
INTRODUCTION
Human fetus is sterile.
Colonization starts at birth.
Within hours – facultative & aerobic bacteria.
2nd day – anaerobic bacteria.
Within 2 weeks – mature microbiota estd in gut.
After weaning - 1014 microorganisms with 400 different type
of bacteria.
There are 10 times more bacteria than human
cells.
4. Page 4
Establishing microbiota - harmony with the host.
Constant renewal - prevents the accumulation of
microorganisms.
Teeth provide hard, non-shedding surfaces - accumulation &
metabolism of bacteria on hard oral surfaces is considered the
primary cause of dental caries, gingivitis, periodontitis and peri-
implant infections.
In the oral cavity, the bacterial deposits have been termed dental
plaque or bacterial plaque.
In 1 mm3 of dental plaque weighing approximately 1mg, approx
1011 bacteria are present. [Socransky et al ,1953]
5. Page 5
Classification of soft deposits
MATERIAL
ALBA
FOOD DEBRIS
A non-cellular thin film
An organized transparent deposit which is
primarily composed of bacteria and their
products
Soft, whitish deposit with no specific
architecture, which can be removed by
water spray.
Retained food which is usually removed by
saliva and oral muscular action.
Schwartz et al 1969
ACQUIRED
PELLICLE
DENTAL
PLAQUE
6. Page 6
Bowen W.H. (1976) defined dental plaque clinically as a structured,
resilient,yellow-grayish substance that adheres tenaciously to the
intraoral hard surfaces, including removable and fixed restorations.
According to Schwartz & Massler (1969) – Plaque is a dense microbial
Layer consisting of coherent mass of filamentous, rod like and coccoidal
microorganisms embedded in an inter microbial matrix which accumulates
on tooth surface.
Davies et al (1963) defined plaque as a soft concentrated mass containing
mainly of large variety of bacteria together with certain amount of cellular
debris which develops within a short time after tooth brushing.
DEFINITIONS
7. Page 7
According to WHO (1978) Plaque is a specific but highly variable
structural entity resulting from colonization and growth of
microorganisms on surfaces of teeth and consisting of numerous
microbial species and stains embedded in a extracellular matrix.
According to the GPT, 4th Edition An organized mass, consisting
mainly of microorganisms, that adheres to teeth, prostheses, and oral
surfaces and is found in the gingival crevice and periodontal pockets.
Other components include an organic, polysaccharide-protein matrix
consisting of bacterial by-products such as enzymes, food debris,
desquamated cells, and inorganic components such as calcium and
phosphate
According to Carranza, 11th Edition Dental plaque is defined
clinically as a structured, resilient yellow-grayish substance that
adheres tenaciously to the intraoral hard surfaces, including
removable and fixed restorations.
8. Page 8
HISTORY
J Leon Williams (1897) – Described dental plaque
GV Black (1899) – Coined term “gelatinous dental plaque”
W D Miller (1902) - Bacterial plaque
Wild (1941) - Shortened Black’s terminology to the term ‘Plaque’
Waerhaug (1950) Described the importance of bacterial plaque in the
etiology of periodontal disease
Loe et al (1965), Landmark study on plaque , saying that plaque is main
etiological agent in periodontal disease.
9. Page 9
Schei (1959), Russel (1967) - Epidemiological studies-
Positive correlation between the amount of bacterial plaque and the severity
of gingivitis
W.Loesche (1976) - Modern theories of specificity – “Specific plaque
hypothesis”
Socransky 1979 - Modern Version of Specific Plaque Hypothesis
Thelaide 1986 - Unified Theory
PD Marsh & Martin (1999) - Ecological plaque hypothesis
Costerton (1999) - Evolved Biofilm
Hajishengallis et al 2012 - Keystone Pathogenic Hpothesis
10. Page 10
I.GRANTS CLASSIFICATION- ACCORDING TO LOCATION
A. Coronal plaque- Coronal to the gingival margin
B. Gingival plaque- forms on the external surface of the oral
epithelium and attached gingiva
C. Sub gingival plaque- located between the periodontal
attachment and the gingival margin, within the sulcus or
pocket.
D. Fissure plaque- develops in pits and fissures
E. Peri-implant plaque.
CLASSIFICATION
11. Page 11
II. GLICKMAN’S CLASSIFICATION- ACCORDING TO
LOCATION
11
13. Page 13 13
TOOTH
ATTACHED
UNATTACHED TISSUE
ATTACHED
Gram +ve,
Few Gram –ve
rods and cocci,
Gram negative
rods, filaments,
spirochetes
Gram negative
rods, filaments,
spirochetes
Does not
extend to JE
Extend to JE Extend to JE
Calculus
formation, root
caries
Gingivitis Gingivitis,
periodontitis
May penetrate
cementum
- May penetrate
epithelium and
connective
tissue
14. Page 14
Pavel Godoroja and Olga Dulghieru 2004
The dental plaque is differentiated into two categories by
Supra-gingival
plaque
Gingival third of the
crown of the tooth
Inter-proximal areas
Pits and fissures and also on
other such surface with
irregularities.
Sub-gingival plaque
Tooth adherent
zone
Epithelial adherent
zone
Non adherent zone
20. Page 20
MICROSCOPIC STRUCTURE
SUPRAGINGIVAL PLAQUE
Typically demonstrates a stratified organization of the bacterial
morphotypes.
Gram-positive cocci and short rods predominate at the tooth
surface
Gram-negative rods and filaments ,spirochetes predominate in
the outer surface of the mature plaque mass.
Supra gingival plaque can have a structured architecture
polymer containing channel or pores have been observed that
link the plaque/oral environment interface to the tooth surface (
Wood et al 2000,Auschillet al 2001,Zaura Arite et al 2001)
21. Page 21
Thin section of supragingival plaque
GRAM POSITIVE BACTERIA IN
PALISADING ARRANGEMENT
22. Page 22
SUBGINGIVAL PLAQUE
Between sub gingival plaque and the tooth an electron dense
organic material is interposed , termed as cuticle.
Gingival crevicular fluid, -contains many substances that the
bacteria may use as nutrients
Host inflammatory cells and mediators have influence on the
establishment and growth of bacteria in this region.
DENTA PLAQUE UNDER
X 400 MAGNIFICATION
23. Page 23
Thin section of plaque in a deep pocket
FILAMENTS
RODS
COCCI
24. Page 24
DEVELOPMENT OF DENTAL
PLAQUE
The formation of the
pellicle on the tooth
surface
Initial adhesion and
attachment of
bacteria
Colonization and
plaque maturation
12/27/2011
25. Page 25
I. Formation of the pellicle
Vigorous tooth brushing – nanoseconds – acquired pellicle .
Acquired pellicle - a homogenous, membranous, acellular film that
covers the tooth surface and frequently form the interface between
the tooth ,the dental plaque and calculus. (Schluger)
`A fully established pellicle - 30 min, within 24 hr- 0.8 µm in
diameter.
Derived from components of saliva and crevicular fluid as well as
bacterial and host tissue cell products and food debris.
12/27/2011
Transmission electron micrograph (TEM) of the acquired pellicle on an enamel surface
26. Page 26
ULTRA STRUCTURE OF DENTAL PELLICLE
Salivary pellicle can be detected on clean enamel surfaces
within 1 minute.
By 2 hours, the pellicle is essentially in equilibrium.
Thickness - 30 - 100 nm
2 hr pellicle: Granular structures which form globules, that
connect to the Hydroxyapatite surface via stalk like structures.
24 hrs Later: Globular structures get covered up by fibrillar
particles : 500 - 900 nm thick
36 hrs Later: The pellicle becomes smooth, globular
(Panacea for Periodontology: Basic Tissue, Etiology and Pathogenesis
By Dr. Priyam Mishra)
12/27/2011
27. Page 27
Studies shows ( 2 hours) enamel pellicle, its amino acids
composition differs from that of saliva, indicating that the
pellicle forms by selective adsorption of the environmental
macromolecules. (Scannapieo FA et al , “ saliva and dental pellicles’”
contemporary periodontics, 1990)
Mechanism involved are:
Electrostatic forces
Van der waals
Hydrophobic forces
12/27/2011
28. Page 28
CHEMICAL COMPOSITION OF ACQUIRED PELLICLE
(Mayhell & Butller 1976, Sonju 1975)
Amino acids -
4.6%
Pellicle contains more hydrophobic and less neutral
amino acids than whole saliva (ie more leucine,
alamine, tyrosine and sereine than saliva)
Hexosamines -
2.7%
Glucosamine - 18%, Galactosamine -18%
Carbohydrates -
14%
Glucose - 20%, Galactose - 27%
Mannose - 9% Fructose - 18%
Salivary Molecules Mucins
Proline rich proteins - statherins
Cystatins, Amylases
Ductal & stromal products
Lactoferrin & Lysozyme
29. Page 29
SIGNIFICANCE
OF PELLICLE
PROTECTIVE
provide barrier
against acids thus
may reduce dental
caries attack.
LUBRICATIONke
p surface moist
prevent drying.
NIDUS FOR
BACTERIA:
Plaque formation
by adherence of
microorganisms.
ATTACHEMENT
CALCULUS: A
of calculus
attachment.
30. Page 30
II. Initial Adhesion and Attachment of
Bacteria
TRANSPORT TO
SURFACE
INITIALADHESION
ATTACHMENT
COLONIZATION OF
SURFACE & BIOFILM
FORMATION
31. Page 31
PHASE I. Transport to the surface
RANDOM CONTACTS
OCCUR THROUGH:
Brownian
motion ( 40
µm/hour)
Sedimentation of
organisms
Liquid flow
Active bacterial
movement
(chemotactic
activity)
12/27/2011
32. Page 32
PHASE II. INITIAL ADHESION
Transport
to surface
Initial
adhesion
Attachment
Colonization
of the
surface and
biofilm
formation
Reversible adhesion of the
bacterium and the surface.
Physical phase
Initiated by interactions b/w bacterium and surface through long
range and short range forces, including
Van der Waals attractive forces
Electrostatic repulsive forces
33. Page 33
DLVO theory
Derjaguin, Landau, Verwey & Overbeek (DLVO) have postulated
that above a separation distance of 1nm, the summation of previous
two forces describes total range interaction also called as Total
Gibbs Energy (GTOT).
The result of summation (GTOT= GA+GE) is function of a
separation distance between negatively charged particle and a
negatively charged surface in a medium ionic strength suspension
medium.
35. Page 35
PHASE III. Attachment
A firm anchorage between bacterium and surface will be
established by specific interactions ( ionic, covalent, or hydrogen
bonding)
This follows direct contact or bridging true extra cellular
filamentous appendages (with length up to 10nm).
12/27/2011
36. Page 36
On a rough surface, bacteria are better protected against shear
forces so that a change from reversible to irreversible bonding
occurs more easily and more frequently.
The bonding between bacteria and pellicle is mediated by
specific extracellular proteinaceous components (adhesions) of
the organism and complementary receptors (proteins,
glycoproteins, polysaccharides) on the surface (pellicle) and is
species specific.
37. Page 37
Streptococci (mainly S. sanguis) – Primary colonizer - binds to
acidic proline-rich-proteins
α-amylase
sialic acid.
Actinomyces - Primary colonizers, eg A. viscosus possesses
fimbrae - adhesins - specifically bind to proline-rich proteins of
dental pellicle.
A. viscosus - reognises cryptic segments [cryptiotopes] of proline
rich proteins, which are only available in adsorbed molecules.
( with lock &key mech.)
( Mergenhagen et al 1987)
Receptors in pellicle
39. Page 39
III. Colonization and plaque
maturation
Mainly by 2
mechanisms
COAGREGGATION. COADHESION
12/27/2011
Transport
to surface
Initial
adhesion
Attachment
Colonization
of the
surface and
biofilm
formation
40. Page 40
PRIMARY COLONIZERS
They provide new binding sites for adhesion by other oral bacteria.
The early colonizers (e.g., streptococci and Actinomyces species) use
oxygen and lower the reduction-oxidation potential of the
environment, which then favors the growth of anaerobic species.
12/27/2011
SECONDARY COLONIZERS
They do not initially colonize the clean tooth surface but adhere to
bacteria already in the plaque mass.
Including Prevotella intermedia, Prevotella loescheii,
Capnocytophaga spp., Fusobacterium nucleatum, and
Porphyromonas gingivalis.
41. Page 41
Co-aggregation is the interaction
between planktonic micro-organisms
of a different strain or species
Co-adhesion is the interaction
between a sessile, already adhering
organism and planktonic micro-
oganisms of a different strain or
species
42. Page 42
Co- Aggregation
It was described by Gibbsons & Nygaard
Cell to cell recognition of a genetically distinct partner cell type.
Occurs primarily through
1. Highly specific interaction of
protiens and carbohydrate
molecules located on the bacterial
cell surfaces.
2. Less specific interaction resulting
from hydrophobic electrostatic &
van der waals forces.
43. Page 43
Well characterized interaction include the coaggregation of:
• Fusobacterium nucleatum S. sanguis,
• Prevotella loescheii A. viscosus
• Capnocytophaga ochraceus A. viscosus
• Streptococci show intrageneric co-aggregation bind to
the nascent monolayer of already bound streptococci.
Later stages – coaggregation between different Gram negative
species seen – F. nucleatum & P. gingivalis or T. denticola.
43
44. Page 44
Coaggregation Bridges:
Formed when the common partner bears two or more types of coaggregation
mediators.
Mediators can be various types of receptor polysaccharides, or various types
of adhesins, or a mixture of the two.
Bridging is usually considered to be a cooperative event that brings three or
more cell types into close proximity and fosters symbiotic relationships.
Bridging can also be an antagonistic event which brings together organisms
that compete with each other for nutrient or other needs.
45. Page 45
Thus most coaggregation among strains of different genera are
mediated by lectin-like adhesin & can be inhibited by lactose &
other glycosides.
46. Page 46
• F.nucleatum is central to the mechanism - since this
organism can co aggregate with numerous other species.
• Examples
F.nucleatum:
S.sanguis
P. loescheii
A.viscous
Capnocytophaga
P.gingivalis
B.forsythus
T.denticola
12/27/2011
48. Page 48
COAGGREGATION COMPETITION:
Competition occurs when multiple cell types recognize the same
coaggregation mediator on the common coaggregation partner.
Model depicting competition for binding sites
on Streptococcus oralis .
49. Page 49
Test tube brush:
Composed of a central axis of a filamentous
bacterium with perpendicularly associated
short filaments.
Commonly seen in the subgingival plaque of
teeth associated with periodontitis
Detected between filaments of bacteria to
which gram –ve rods adhere.
Corncob formation:
Feature of plaque present on teeth
associated with gingivitis .
Rod-shaped bacterial cells eg.
Bacterionema matruchotii or
Actinomyces sp. that forms inner core
of the structure and coccal cells eg.
Streptococci or P. gingivalis that attach
along the surface of the rod shaped
cells.
Described by Gibbsons and Nygaard
50. Page 50
S.mitis
S.oralis
S.sanguis
Streptococcus sps
S.gorondi,
S.intermedius
E
A
R
L
Y
C
O
L
O
N
I
Z
E
R
S
V.parvula
A.odontolyticus
P.intermedia
P.nigrescens
P.micros
F.nucleatum
C.rectus
E.nodatum
C.showae
E.corrodens
Capnocytophaga sps
A.actinomycetocomitans
P.gingivalis
T.forsythus
T.denticola
CLOSELY ASSOCIATED
COMPLEXES IN THE ORAL
CAVITY
LATE COLONIZERS
12/27/2011
Socransky et al (1998)
51. Page 51
Distribution of different complexes in subgingival plaque
sample
Kigure et al (1995)
52. Page 52
CO-ADHESION
• Some bacteria are unable to bind directly to the conditioning
film, but are able to interact with molecules on bacteria that
are already attached (co-adhesion), also by adhesin-receptor
interactions.
• One bacterium, Fusobacterium nucleatum, can co-adhere with
almost all other bacteria found in dental plaque, and is
considered to be a key bridging organism between early and
later colonisers.
53. Page 53
Development of dental plaque on a clean enamel surface. Coccal bacteria attach to the enamel pellicle as pioneer species
(A) and multiply to form microcolonies (B), eventually resulting in confluent growth (biofilm formation) embedded in a
matrix of extracellular polymers of bacterial and salivary origin (C). With time, the diversity of the microflora increases, and
rod and filament-shaped bacteria colonize (D and E). In the climax community, many unusual associations between
different bacterial populations can be seen, including ‘corn-cob’ formations (F). (Magnification approx. × 1150)
