Glossary entry
Dental Calculus
Also called: Tartar, hardened plaque
Dental calculus is mineralized dental plaque — biofilm that has calcified through saliva- or crevicular-fluid-derived mineral precipitation — requiring mechanical instrumentation for removal.
What is dental calculus?
Dental calculus is plaque biofilm that has mineralized into a hard deposit. Supragingival calculus forms predominantly from saliva-derived calcium and phosphate; subgingival calculus forms from gingival crevicular fluid and is typically darker due to blood pigments.
Once calcified, calculus cannot be removed by home care — biofilm on its rough surface is protected and accumulates continuously, making calculus a biologically active risk factor for gingivitis and periodontitis. Calculus is cleared by hand instruments, ultrasonic scalers, or a combination.
When is it used?
Calculus removal is the core of every prophylaxis and non-surgical perio appointment. Calculus burden at recall also informs recall interval adjustments.