Etiology, Contributing Factors and Link to Systemic Disease Flashcards
Define risk factor
A characteristic that places and individual at increased risk of contracting a disease
Define risk indicator
A probable or putative risk factor that has been identified in cross-sectional correlation studies but not confirmed through longitudinal studies
4 risk factors for periodontitis
- Diabetes
- Inadequate oral hygiene
- Genetics
- Smoking
8 risk indicators for periodontitis
- Socio-economic status
- Obesity
- Stress
- Age
- Contraceptives
- Alcohol
- Race
- Sex
Define etiology
The study or theory of the causation of a disease
A single or a cluster of factors that contribute to disease
Role of bacterial plaque in periodontal disease
Necessary but not sufficient to cause disease
Primary etiologic factor of periodontitis
Microbial plaque
Secondary etiologic factor of periodontitis
Calculus (most significant local contributing factor)
3 characteristics of bacteria related to health
- Gram positive
- Facultatives anaerobes
- Generally non motile
i.e. streptococcus anguis and mitus, actinomyces viscosus, israelli and naeslundi
3 characteristics of bacteria related to disease
- Gram negative
- Strict anaerobes
- Motile & non-motile forms
What is the pathogenic potential of calculus?
- Plaque retention
- Production of an inflammatory reaction in the tissue
3 bacterial species in the red category
- P. gingivalis
- T. forsythensis
- T. denticola
11 local and anatomical factors contributing to periodontal disease
- Root morphology
- Furcation
- Cervico-enamel projections (CEP)
- Enamel pearls
- Palatogingival grooves
- Root proximity
- Food impaction/open contacts
- Marginal ridge discrepancy (plunger cusp)
- Restorations (quality of restorative margins, contours, curvatures, etc)
- Position of tooth
- Caries
Anatomic variation of furcation that creates a protected environment for plaque and calculus collection
Internal intra-radicular root concavities
Significance of accessory canals for periodontal disease
Communication between the pulp and the furcation
Endo-perio or perio-endo lesions
How do cervico-enamel projections contribute to periodontal disease?
Acts like a pathway for transferring the plaque to the furcation
Define enamel pearls
Localized masses of enamel that develop ectopically, typically over the root surfaces in close proximity to the CEJ
How do open contacts contribute to periodontal disease?
Food impaction
Define palato-gingival groove
Groove in the enamel of the tooth leading into the gingiva. Site of bacterial and plaque accumulation.
7 systemic factors contributing to periodontal disease
- Smoking
- Stress
- Medical conditions
- Medications
- Genetics
- Age
- Sex
4 effects of smoking on periodontium
- Increases the prevalence and severity of destruction
- Increase in PD, CAL and bone loss
- Increased rate of destruction
- Increased number of tooth loss
NOTE: These negative effects are cumulative over time with increased smoking. However, these same effects will decrease with cessation
Mechanism of periodontitis associated with diabetes
- Altered neutrophil response
- Upregulation of monocutes –> hyper-inflammatory response
- AGE-RAGE interaction may lead to increased production of inflammatory cytokines in the diabetic patient
Earlier theory of etiology of periodontal disease (5 points)
- All individuals are equally susceptible to periodontitis
- Always starts with gingivitis and if not treated will progress to periodontitis
- As people age the chances of getting periodontitis goes higher
- Plaque, calculus and other local factors are the only contributors to periodontal disease
- NO ROLE OF HOST SUSCEPTIBILITY
Today’s theory of etiology of periodontal disease
- Not all individuals are equally susceptible to periodontal disease
- Gingivities doesn’t always progress to periodontitis
- Prevalence and severity of periodontal disease increased with age but susceptibility to future periodontal disease is not dependent upon age
- Systemic and environmental factors play a role in progression of the disease
- BUT HOST SUSCEPTIBILITY PLAYS A MAJOR ROLE
Define the non-specific plaque hypothesis
Periodontal disease results from the “elaboration of noxious products by the entire plaque flora”. If small amounts of plaque are present, the noxious products are neutralized by the host. But if large amounts are present, this overwhelms the host’s defenses.
The control of periodontal disease depends on control of the amount of plaque accumulation
Define the specific plaque hypothesis
- Only certain plaque is pathogenic, and its pathogenicity depends on the presence of or increase in specific microorganisms
- Acceptance of this hypothesis was spurred by the recognition of a.a. as a pathogen in localized aggressive periodontitis
Define biofilm
Multi-species community of microorganisms that adhere to each other and a surface, and are encased in an extracellular matrix
Define virulence factor
The unique properties which permit a bacterial species to colonize a target organ, defend itself from the host and cause tissue damage
2 categories of virulence factors
- Factors favoring bacterial adherence and colonization
- Factors which mediate host tissue destruction
Adherence factors of subgingival species
Adhesions including fimbriae and cell-associated proteins
Define lipopolysaccharides
Large molecules composed of a lipid component (lipid A) and a polysaccharide component. They are found in the outer membrane of gram-negative bacteria. Act as andotoxins and elicit strong immune responses.
5 host defense mechanisms that must be overcome to induce periodontitis
- Salivary and gingival crevicular fluid flow
- Mechanical displacement (i.e. tissue desquamation)
- Specific antibodies
- Host products (i.e. glycoproteins that block bacterial cell binding)
- Cells of the immune system
2 bacterial mechanisms that may mediate host tissue damage
- Invasion of the tissue by pathogens
- Diffusion of bacterial byproducts from the crevice into the gingival tissues
4 examples of bacterial byproducts that may diffuse from the crvice into the gingival tissues to mediate host tissue damage
- Ammonia (NH)
- Hydrogen sulfide (HS)
- Short-chain carboxylic acids (i.e. butyric acid and propionic acid)
- Proteases
Define yellow complex bacteria
Early colonizers; most associated with caries formation