Tartar, medically known as dental calculus, is a hard, crusty deposit that forms on the surface of teeth. Because it is essentially hardened dental plaque, it cannot be removed through brushing alone and requires professional intervention. Understanding the biological process of its formation, which begins as a soft, invisible film, is key to managing its buildup.
The Precursor: Understanding Dental Plaque
The formation of tartar starts with dental plaque, a soft, sticky, and colorless film that constantly forms on teeth. Plaque is a complex microbial community, or biofilm, composed primarily of bacteria, salivary proteins, and food particles that adheres to the tooth surface.
This biofilm begins to form almost immediately after brushing or professional cleaning. Plaque formation starts when bacteria attach to the acquired pellicle, a thin layer of salivary glycoproteins coating the enamel. The bacteria then multiply and build a complex, three-dimensional structure embedded in a matrix of substances they produce.
If not removed regularly, this soft plaque grows thicker, especially along the gumline and between teeth. The bacteria within the plaque feed on sugars and carbohydrates, releasing acids that can weaken tooth enamel. Because plaque is soft, it can be effectively removed through daily mechanical hygiene, such as brushing and flossing.
How Plaque Hardens into Tartar
The transformation of soft plaque into hard tartar is a process called mineralization or calcification. Minerals naturally present in saliva, specifically calcium and phosphate ions, begin to precipitate into the plaque matrix.
The precipitation of these minerals into the biofilm effectively hardens the soft, sticky mass into a dense, rock-like deposit known as calculus. Plaque can start to calcify into tartar in as little as 24 to 72 hours if it is not removed. Once the minerals have been incorporated, the resulting tartar is firmly attached to the tooth surface and cannot be removed by any home care method.
The hardened tartar serves as a rough, porous surface that attracts and retains even more plaque, accelerating further buildup. This creates a cycle where existing tartar promotes the formation of new layers. The specific time it takes for calcification varies among individuals based on factors like the pH of their saliva and the concentration of mineral salts present.
Health Consequences and Necessary Removal
The presence of hardened tartar is a significant threat to oral health because its rough surface allows for the continuous accumulation of new plaque and bacteria. Tartar buildup near the gumline irritates the gum tissue, often leading to gingivitis, the earliest form of gum disease characterized by redness and inflammation.
If tartar is left unchecked, the inflammation can progress to periodontitis, a more advanced stage of gum disease. In periodontitis, the gums pull away from the teeth, creating infected pockets. This allows bacteria to destroy the underlying bone and tissue structures supporting the tooth. Uncontrolled periodontitis is a leading cause of tooth loss and has also been associated with broader systemic health issues.
Because tartar is strongly bonded to the tooth, professional dental treatment is the only effective way to remove it. Dental hygienists use specialized tools, such as ultrasonic scalers and dental hand instruments, to scrape the hard calculus from both above and below the gumline. This procedure is called scaling and root planing, and it is performed during regular dental cleanings, which are typically recommended every six months to manage buildup and prevent the progression of gum disease.