Upload
ceudmd3d
View
228
Download
7
Embed Size (px)
Citation preview
7/31/2019 7 Etiology of Periodontal Disease
1/37
Etiology of PeriodontalDisease
Dr. Marcel Hallare
7/31/2019 7 Etiology of Periodontal Disease
2/37
Periodontal disease is a pathologic processthat affects the periodontium
The vast majority of inflammatory diseasesof the periodontium results from bacterial
infection The dominating causative agents of
periodontal disease are microorganisms thatcolonize the tooth surface (bacterial plaque
and products) No systemic disorder is known to be the
initiating cause of periodontitis in theabsence of bacterial plaque
7/31/2019 7 Etiology of Periodontal Disease
3/37
TOOTH-ACCUMULATED MATERIALS
1. Bacterial plaque2. Acquired pellicle
3. Calculus
4.
Food debris5. Materia alba
7/31/2019 7 Etiology of Periodontal Disease
4/37
Bacterial plaque
Two types of plaque that are closelyassociated with periodontal disease:
1. Consists of a mat of densely packed,colonized, and colonizing microorganismsthat grow on and attach to the tooth
2. Free floating or loosely attached betweenthe soft tissue and teeth
7/31/2019 7 Etiology of Periodontal Disease
5/37
Acquired pellicle
Primarily a protein film that forms onerupted teeth and can be removed byabrasives
Quickly reforms after being removed
Not removed by forceful rinsing
7/31/2019 7 Etiology of Periodontal Disease
6/37
Calculus
Calcified plaque that is usually coveredby a soft layer of bacterial plaque
7/31/2019 7 Etiology of Periodontal Disease
7/37
Food debris
Food matter that is retained in the mouth
7/31/2019 7 Etiology of Periodontal Disease
8/37
Materia alba
(literally, white matter)A soft mixture of salivary proteins, some
bacteria, many desquamated epithelialcells, and occasional disintegrating
leukocytes Usually flushed off with forceful water
spray
7/31/2019 7 Etiology of Periodontal Disease
9/37
BACTERIAL FACTORS INPERIODONTAL DISEASE
7/31/2019 7 Etiology of Periodontal Disease
10/37
Morphology of BacterialPlaque
Under light and SEM, supragingivalplaque and subgingival plaque havedistinct morphological differences
7/31/2019 7 Etiology of Periodontal Disease
11/37
Supragingival Plaque
Bacterial cells appear to be denselypacked on the tooth surface and thedeposits may be thick (0.5mm or more)
Composition of the microbial deposits
includes coccoid and relatively numerousfilamentous bacteria
7/31/2019 7 Etiology of Periodontal Disease
12/37
Some filamentous bacteria are coveredwith coccal organisms, which appear as
corncob formations
Flagellated forms and spirochetes areobserved apically and on the outer
surface
7/31/2019 7 Etiology of Periodontal Disease
13/37
Subgingival Plaque
Subgingival plaque in periodontitispatient is composed of an inner and anouter layer
The inner layer is tightly adherent
bacteria is continuous with, but is thinnerand less organized than supragingivalplaque
7/31/2019 7 Etiology of Periodontal Disease
14/37
Outside this tightly adherent layer, andadjacent to the soft tissue of the pocket,is a loosely adherent layer ofmicroorganisms
This layer consists of numerousspirochetes, gram-negative bacteria, and
bacteria grouped into bottle-brush ortest-tube brush formations
7/31/2019 7 Etiology of Periodontal Disease
15/37
Microorganisms of Plaque
Young plaque (1-2 days) consistsprimarily of gram-positive and somegram-negative cocci and rods
From 2-4 days of growth, undisturbed
plaque changes in the numbers and thetypes of organisms present
7/31/2019 7 Etiology of Periodontal Disease
16/37
The number or gram-negative cocci androds increase and fusiform bacilli and
filamentous organisms becomeestablished
From 4-9 days, this ecologically complexpopulation of microorganisms is further
complicated by the presence of theincreasing number of motile bacteria,namely, spirilla and spirochetes
7/31/2019 7 Etiology of Periodontal Disease
17/37
1. Epithelial cells2. White Blood cells
3. Erythrocytes
4. Protozoa
5. Food particles
6. Miscellaneous components
Other Constituents of Plaque
7/31/2019 7 Etiology of Periodontal Disease
18/37
Mechanism of Bacterial Action
1. Invasion2. Cytotoxic agent
3. Enzymes
4. Immunopathologic mechanism
5. Combined action
7/31/2019 7 Etiology of Periodontal Disease
19/37
Invasion
Bacterial invasion is not necessary forgingival inflammation to occur
All that is required id that enoughbacteria (and possibly specific pathogenic
bacteria) be fixed to the tooth, near thegingiva, for sufficient length of time tochallenge the tissue with their toxicproducts
7/31/2019 7 Etiology of Periodontal Disease
20/37
Cytotoxic agent
Endotoxins, which are lipopolysaccharideconstituents of the cell wall of gram-negative bacteria, can be a direct causeof tissue necrosis, as well as initiator of
inflammation by triggering animmunologic response and activation ofthe complement system
7/31/2019 7 Etiology of Periodontal Disease
21/37
Enzymes
Collagenasedepolymerizes collagen
fibers and fibrils, the major formedelements in the gingiva and periodontalligament
Proteases, a family of enzymes,contribute to breakdown of non-collagenous proteins and increasecapillary permeability
7/31/2019 7 Etiology of Periodontal Disease
22/37
Hyaluronidasehydrolyzes hyaluronic acid,an important tissue cementingpolysaccharide, and can act as a
spreading factor to increase tissuepermeability
Chondroitinasehydrolyzes chondroitin
sulfate, another tissue-cementingpolysaccharide
7/31/2019 7 Etiology of Periodontal Disease
23/37
Immunopathologic mechanism
The role of the immunologic response inperiodontal disease is not completelyunderstood; however, the potential tocause tissue destruction is apparent
7/31/2019 7 Etiology of Periodontal Disease
24/37
Combined action
It is possible that more than onemechanism may be involved in theinitiation and progression of inflammatoryperiodontal disease
7/31/2019 7 Etiology of Periodontal Disease
25/37
SYSTEMIC FACTORS ANDPERIODONTAL DISEASE
Any condition that might reduce theresistance of periodontium to toxic insultshould be expected to contribute to theinitiation of the inflammation and to
influence the rapidity and severity of thedisease process
7/31/2019 7 Etiology of Periodontal Disease
26/37
LOCAL CONTRIBUTING FACTORSAND PERIODONTAL DISEASE
1. Anatomic factors2. Iatrogenic factors
3. Calculus formation
4. Traumatic factors
5. Chemical injury
6. Excessive occlusal force
7/31/2019 7 Etiology of Periodontal Disease
27/37
Anatomic factors
Root morphology Position of tooth in arch
Root proximity
7/31/2019 7 Etiology of Periodontal Disease
28/37
Iatrogenic factors
Operative procedures Restorative materials and restorations
Removable partial dentures
Fixed partial denture Exodontics
Orthodontics
7/31/2019 7 Etiology of Periodontal Disease
29/37
Calculus formation
Important in the progression of disease Serves as a coral reef within which
microorganisms can multiply and releasetheir toxic products
The rough surface of calculus makes itdifficult if not impossible, for the patientto remove associated bacterial plaque
7/31/2019 7 Etiology of Periodontal Disease
30/37
Traumatic factors
Toothbrush abrasion Factitious disease
Food impaction
7/31/2019 7 Etiology of Periodontal Disease
31/37
Chemical injury
Indiscriminate use of topically appliedaspirin tablets, strong mouthwashes, andvarious escharotic drugs may result inulceration of the gingival tissue
7/31/2019 7 Etiology of Periodontal Disease
32/37
Excessive occlusal force
7/31/2019 7 Etiology of Periodontal Disease
33/37
Neoplasms
7/31/2019 7 Etiology of Periodontal Disease
34/37
Renewal of GingivalEpithelium
The oral epithelium undergoescontinuous renewal
Its thickness is maintained by a balancebetween new cell formation in the basal
and spinous layers and the shedding ofold cells at the surface
7/31/2019 7 Etiology of Periodontal Disease
35/37
Mitotic activity exhibits a 24-hourperiodicity, with highest and lowest ratesoccurring in the morning and eveningrespectively
Mitotic rate is highest in nonkeratinizedareas and is increased in gingivitis,without significant gender differences
7/31/2019 7 Etiology of Periodontal Disease
36/37
Turnover times of tissue:
palate, tongue, cheek 5-6 days
gingiva 10-12 days
junctional epithelium 1-6 days
7/31/2019 7 Etiology of Periodontal Disease
37/37
The End