Dental Calculus

### Dental Calculus

• Mineralized bacterial biofilm
• Forms 48 hours - 2 weeks after plaque formation
• Composed of 10-30% organic and 70-90% inorganic material

Composition

• Organic: Plaque bacteria, dead epithelial cells and white blood cells
• Inorganic: Calcium, phosphate, magnesium, magnesium phosphate, calcium carbonate

Crystalline Structure

• Calcium brushite
• Octocalcium phosphate
• Calcium hydroxyapatite
• Magnesium whitlockite

Crystalline Content Variation

• Can vary due to location: anterior or posterior, supra or sub, and age of calculus
• Can also differ based on the individual

Relevance

• Significant role in the progression of dental disease
• Contributes to gingivitis and periodontitis

Other Locations

• Common sites of attachment: gingival crevice, root surface with periodontal pockets, prosthesis, restoration ledges, imbricated teeth, occlusal surfaces

Sub vs. Supra Calculus

• Supragingival calculus is above the gum line
• Subgingival calculus is below the gum line
• Subgingival calculus can become supragingival calculus based on location and other factors

Method of Attachment

• Acquired pellicle
• Penetration into enamel, cementum or dentine
• Tooth irregularities from previous instrumentation

Calculus Formation

• Organic matrix acts as a seeding agent
• Phosphatases and proteases from bacteria degrade calcification inhibitors in saliva
• This leads to the formation of insoluble calcium phosphate crystals, which coalesce to form calcified mass of plaque known as calculus

Calculus Formation Rate

• Varies from person to person
• Different teeth can be affected differently
• Can vary over time in the same person
• Individuals can be classified as heavy, moderate, slight, or non-calculus formers

Detection

• May be visible clinically
• Can be detected on radiographs

Clinical Impact

• Calculus contributes to periodontal disease
• Influences plaque accumulation
• Harbors bacteria
• Contributes to inflammation and tissue destruction
• Creates difficult-to-clean surfaces
• Can lead to gingival recession and tooth mobility
• Can affect restorative procedures and implant stability

Impact on Clinician and Patient

• Clinicians need to educate patients on calculus and its impact on oral health
• Regular dental cleanings are important to remove calculus and prevent its formation
• Patients need to maintain good oral hygiene practices at home