Historic background Before 1960calculus is the primary cause for periodontal disease

Current viewsplaque is the nidus

Definition Calculus is the hard deposit that forms by mineralization of dental plaque and is generally covered by a layer of unmineralized plaque. Calculus consist of mineralized bacterial plaque that forms on the surface of natural teeth and dental prosthesis

Types of dental calculusCalculus

Supra gingival

Sub gingival

Supra gingival calculusCoronal to gingival margin

Supragingival calculus is depicted on the buccal surfaces of maxillary molars adjacent to orifice for Stensons duct.

Extensive supragingival calculus on the lingual surfaces of lower anterior teeth.

Sub gingival calculusApical to gingival margin

Differences and prevalences

Different shapes of calculus on extracted teeth.

Sub gingival calculus interdental area

Dark pigmented deposits of subgingival calculus on the distal root of an extracted lower molar.

Composition of calculus Inorganic 70-90 % ca - 27-29 % Ph - 16 -18 % Carbonate 2 -3 % Na 1.5 -2.5 % Mg .6 - .8 % F .003 -.004 %

Inorganic Protein, poly sac ,epi cell ,lueko -1.9 -9.1 % Protein 5.9 8.2% Lipids .2 % Salivary glycoprotein galactose ,glucose, rhamnose,glucoronic acid

Inorganic component in crystal form Brushite 9% Hydroxyappatite 58 % Octa calcium phosphate - 12 % Whitlokite 21 %

Formation of calculus Mineralization starts at 50 % mineralize 60 -90% mineralize Maximum 1 to 14 days 2 nd day 12 days 10 week -6 month

Attachment of calculus By org pellicle Mech inter locking to surface irregularities Close adaptation to slopes Penetration of bacteria into cementum

Theories of calculus formation Precipitation of Ca and Ph ionsbooster mechanism Colloidal protein from saliva Phosphate liberated from plaque

Epitactic concept heterogeneous nucleation Inhibitory theory

Etiologic significant Interfere with normal cleaning mechanism Calculus is not a direct irritant -but close contact

Heavy calculus deposit on facial surface of lower cuspid with associated gingival recession.

Removal of plaque and calculus is the corner stone of periodontal therapy

Other predisposing factors

Iatrogenic factors Inadequate dental procedure that contribute to the deterioration of periodontal status Restoration RPDLocation of gingival margin Spaces Contour Occlusion Materials Procedures Design of RPD

Margin of restoration Change in ecology of sulcus Inhibit access to plaque control

Proximal restoration Removal of margin Sub gingival and supra gingival margins Rubber dam/matrix band Gingival cord

Overhanging margin of restoration and atrophied and inflamed gingival papilla.

Inflamed marginal and papillary gingiva adjacent to an overcontoured porcelainfused to metal crown on the maxillary left central.

Contour / Open contact Over contour Food impaction

Factorsuneven occl wear Open contact Extrusion Congenital morphologic abnormality Improper restoration Over bite

Plunger cusp

materials Self cure acrylic Other- biocompatible

Plaque retention psuedo pocket /inflammation

Inflamed palatal gingiva associated with a maxillary provisional acrylic partial denture.

Design of RPD Plaque accumulation Quantitative and qualitative [spirochete]

Mal occlusion

Tongue thrusting and mouth breathing

Anterior open bite with flared incisors as observed in association with a habit of tongue thrusting.

Ortho related Band / elastics Excessive forces Impacted canine extraction Bone height

Maxillary central incisors in which an elastic ligature was used to close a midline diastema.

A lower incisor depicting a prominent root without any attached gingiva and accompanying gingival recession.

Habit and self inflicted injuries Tooth pick wedging Finger nail bite Pizza burn Tooth brush trauma Smoking

A maxillary canine that illustrates gingival recession due to self-inflicted trauma by the patients fingernail.

Tobacco stains on the apical third of the clinical crown due to cigarette smoking.

Radiation therapy Ischemia ,fibrosis ,hypoxic, hypo vascularisation Mucositis, dermatitis fibrosis,trismus,osteoradionecrosisAntibiotics Atraumatic surgery Culture and sensitivity test Less LA usage vaso constictors Hyperbatic oxygen therapy

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