Plaque Induced Gingivitis Aggravated with local Factors: Plaque Induced Gingivitis Aggravated with local Factors )Chapter 10 (10 th ed. Chapter 22 (11 th ed.)
PowerPoint Presentation: The primary cause of periodontal disease is bacterial plaque, along with other predisposing factors. Predisposing factors include calculus, malocclusion, faulty restorations, complications associated withorthodontic therapy, self induced injuries, tobacco and radiation therapy
I Calculus: I Calculus Mineralized bacterial plaque that forms on natural teeth and restorations Calculus is divided to : Supragingival Subgingival
Calculus: Calculus
Prevalence: Prevalence Anerud et. Al.,1991 study Comparison between Sri Lankan tea labors and Norwegian academicians for 15 years … .Develop calculus shortly after teeth eruption Maximum calculus at 25-30 years … .80% showed calculus only on lingual surfaces of lower teeth and buccal surfaces of upper teeth with no longer progression
Composition: Composition Inorganic content: 39% calcium 19% phosphorus 1.9% carbon dioxide 0.8 % magnesium Crystals of: Hydroxyappatite:58% Magnesium White Lockite 21% Octacalsium phosphate 12% Brushite 9%
Organic Contents: Organic Contents 1.9-9.1% carbohydrates: galactose, glucose,.. 5.9-8.2% proteins: amino acids 0.2% natural fates: free fatty acids
Attachment to Tooth Surface: Attachment to Tooth Surface 1- By organic pellicle
PowerPoint Presentation: 2- Mechanical locking into surface irregularities
PowerPoint Presentation: 3- Close adaptation of calculus to gently sloping mounds of untreated cementum
PowerPoint Presentation: 4-Penetration of calculus bacteria into cementum ( not acknowledged by all investigations)
Formation of Cementum: Formation of Cementum 1- Mineralization theory: a) Increase in pH due to loss of CO2 & ammonia produced by bacteria b) Colloid proteins in saliva binds calcium and phosphate c) Phosphatase liberated from plaque bacteria precipitate calcium phosphate
PowerPoint Presentation: 2- Seeding agents induce small foci of calcification that enlarge and coalesce to form a calcified mass( epitactic concept, heterogeneous nucleation) The seeding agent is suspected to be intracellular matrix of bacteria
Role of bacteria: Role of bacteria plaque mineralization start extracellular Some bacteria have liability to form intracellular apatite crystals (diphtheroids & veillonella) Bacteria form phosphatases, change pH leading to mineralization Correlation between plaque and gingivitis is more strong than that between calculus and nacteria
Etiologic Significance: Etiologic Significance The non mineralized surface of calculus is the main irritant
Materia Alba, Food debris and Stains: Materia Alba, Food debris and Stains Materia alba: bacteria, desquamated cells, leukocytes that lacks regular pattern Yellowish to grayish whit, sticky but less adherante
Stains: Stains
II Iatrogenic Factors: II Iatrogenic Factors 1- Margins of restorations Position of restorations: Supragingival, gingival and subgingival Roughness of subgingival margins may be caused by:
PowerPoint Presentation: 1- Grooves and scratches in surface of restorations 2- Separation of restoration margin and luting material 3- Dissolution of luting material 4- Inadequate margin fit
Overhanging margins of restorations: Overhanging margins of restorations
Over contoured margins of restorations: Over contoured margins of restorations
Poor fitting restorations: Poor fitting restorations
Marginal leakage: Marginal leakage
Orthodontic appliance: Orthodontic appliance
Trauma: Trauma
Trauma: Trauma
Chemical burn: Chemical burn
Injurious dental material: Injurious dental material
Tobacco chewing: Tobacco chewing
Anatomic Variations: Anatomic Variations
Readings: Readings Carranza's Clinical Periodontology !0 th edition : Chapter 10 : 270-280 11 th edition: Chapter