ETIOLOGY OF PERIODONTAL DISEASE• The clinical manifestations of periodontal disease result form a complex interplay between bacteria found in dental plaque and the host tissues.• Etiological factors in periodontal disease are classified into two broad categories, depending on their specific origin.
Primary Local Factors (dental plaque Secondary (plaque retention factors) Systemic factors(modify the response of the gingiva to local factor)
Dental plaque Calculus Tobacco UseIatrogenic Local factors Orthodontic Factors Therapy Design of Removable Partial Restorative Malocclusion Dentures Dentistry Procedures
Dental Plaque Dental plaque can be defined as the soft depositsthat form the biofilom adhering to the toothsurface or other hard surfaces in the oral cavity,including removable and fixed restorations.
Supragingival plaque Sub gingival plaqueMarginal plaque
• The different regions of plaque are significant to different processes associated with diseases of the teeth and periodontum.
Plaque Composition1_Microorganisms which exits within an intercellular matrix.Gram positive: S. sanguis, A. viscousus.(initial colonizers)Gram negative: P. intermedia,F.nucleatum.(secondary colonizers)
Plaque Composition2_The intercellular matrix consists of :• Organic constituents of the matrix include polysaccharides, proteins, glycoproteins and lipid material.• Inorganic component of plaque is predominately calcium and phosphorus and other minerals such as sodium, potassium and fluoride
Clinical fissure• White, greyish or yellow in colour.• Globular appearance.• ON gingival third of the tooth surface.
Plaque Formation• Dental pellicle.• Initial colonization( G. positive)• The plaque mass matures (colonization and growth of additional species)• G .negative anaerobic.• Dental plaque may be visualized on teeth after 1 or 2 days without oral hygiene measures.
Association between plaque microorganisms and Periodontal Diseases.a. Nonspecific plaque hypothesis : that periodontal disease results from the elaboration of noxious products by the entire plaque flora.b. Specific Plaque Hypothesis: that only certain plaque is pathogenic and its pathogenicity depends on the presence or increase in specific microorganisms.
1. Calculus Consist of mineralized bacterial plaque that forms on the surfaces of natural teeth and dental prostheses.
Supra gingival calculus mostly formed in thebuccal surfaces of the maxillary molars and thelingual surfaces of the mandibular anterior teeth. When the gingival tissues recede, sub gingivalcalculus becomes exposed.
Formation of calculus Between the first and 14th days of plaqueformation(4 to 8 hours).Saliva supra gingival calculusG. Fluid sub gingival calculus.Calcification begins along the inner surface ofthe plaque.
There are a positive correlation between thepresence of calculus and the prevalenceof gingivitis but this correlation is not asimportant as that between plaque andgingivitis.
2. Dental Stains• Dental stains may lead to tissue irritation by creating a rough tooth surface, which contributes to plaque accumulation and retention.
3. Iatrogenic Factors Deficiencies in the quality of dental restorations or prostheses are contributing factors for gingival inflammation and periodontal destruction.
Iatrogenic Factorsa. Over hanging Margins of Restorations.
Iatrogenic Factorsb. Over contoured crown : Over contoured crowns and restorations tend to accumulate plaque possibly prevent the self- cleaning mechanisms of the adjacent cheek, lips and tongue.
Iatrogenic Factors c. Open Contacts:• Food particles create a favourable environment for plaque accumulation.• Acts as a direct mechanical irritant to the tissue.
9. Tobacco usethe smokers had more sites with:Deep pocketsGreater attachment loss andsevere periodontal disease.
Effects of tobacco use:• Diminish host response and increase disease susceptibility.• Less numbers of T- lymphocytes and less antibody production and serum levels of IgG.• Reduce serum IgG antibobies to P. intermedia and F. nucleatum.• Diminish neutrophils chemotaxis, phagocytosis or both.• Nicotina decrease gingival blood flow.
Bibliography Carranza´s. Clinical Periodontology. 9th ed. 2003. pg:15-55. Gururaja R. Textbook of Periodontology. 2nd ed. pg: 6. Klaus H. Color Atlas of Dental Medicine. Periodontology. Vol 1. 1989. pg: 1- 10.