Tartar is hardened dental plaque, a crusty deposit that forms on your teeth when the soft, sticky film of bacteria in your mouth absorbs minerals from your saliva and solidifies. Once plaque hardens into tartar, you can’t brush or floss it away. It requires professional removal by a dentist or hygienist. About 80% of tartar by weight is mineralized material, primarily calcium and phosphorus, while the remaining 20% is organic matter including proteins, carbohydrates, and bacteria.
How Plaque Becomes Tartar
Tartar starts as plaque, the soft bacterial film that coats your teeth throughout the day. Plaque forms when bacteria in your mouth feed on sugars and starches from food. If plaque stays on your teeth long enough, calcium and phosphate ions in your saliva begin to seep into it, gradually replacing the soft material with hard mineral crystals. This process can begin in as little as four to eight hours, though on average it takes 10 to 12 days for plaque to fully mineralize into tartar.
Once that mineral exchange is complete, the deposit is essentially a layer of calcium phosphate crystals bonded to your tooth surface. The primary mineral is hydroxyapatite, the same compound that makes up tooth enamel and bone, along with smaller amounts of magnesium, sodium, iron, and fluoride. This is why tartar feels rock-hard and why no amount of brushing can dislodge it.
Two Types Based on Location
Tartar that forms above the gumline is called supragingival calculus. It’s the yellowish or off-white buildup you can actually see on your teeth, most commonly along the lower front teeth and near the openings of salivary glands. While it doesn’t directly destroy gum tissue, it creates a rough surface that traps more plaque and makes daily cleaning harder, which accelerates further buildup.
Tartar that forms below the gumline, called subgingival calculus, is more concerning. It’s darker in color, often brown or black, because it absorbs pigments from blood in inflamed gum tissue. You can’t see it, but it sits in the narrow space between your teeth and gums. A two-year study of early gum disease in adolescents found that the presence of subgingival calculus was the single factor most strongly associated with subsequent loss of gum attachment to the teeth. This type of tartar is largely responsible for the progression of chronic periodontal disease.
How Tartar Damages Your Gums and Teeth
Tartar itself isn’t what causes the damage. The problem is the bacteria it harbors. Tartar’s rough, porous surface is an ideal breeding ground for bacterial colonies, and those colonies sit in constant contact with your gum tissue. The longer tartar stays in place, the more bacterial toxins irritate the gums, triggering an immune response that shows up as redness, swelling, and bleeding. This early stage is gingivitis.
Left untreated, that chronic inflammation progresses to periodontitis. Your gums begin pulling away from the teeth, forming deep pockets that fill with more plaque, tartar, and bacteria. As the pockets deepen, the infection reaches the bone and connective tissue that hold your teeth in place. Over time, this causes bone loss and loosening of teeth. The progression from gingivitis to periodontitis isn’t inevitable, but tartar buildup is one of the biggest accelerators because it makes the bacterial exposure constant and impossible to clean on your own.
Signs You Have Tartar Buildup
You can often spot supragingival tartar yourself. It appears as a hard, yellowish or brownish deposit along the gumline, particularly on the inside surfaces of your lower front teeth. Your teeth may feel rough when you run your tongue over them, even after brushing. Other signs include persistent bad breath, gums that bleed when you brush or floss, and gums that look red or puffy rather than firm and pink.
Subgingival tartar is trickier because it’s hidden. You might notice your gums are tender, that they bleed easily, or that they seem to be receding. Your dentist or hygienist can detect it during a routine exam using a thin probe that measures the depth of the space between your gums and teeth.
How Tartar Is Removed
Professional cleaning is the only safe way to remove tartar. During a standard cleaning, your hygienist uses a metal scaling instrument or an ultrasonic device to chip and vibrate the hardened deposits off your tooth surfaces, both above and below the gumline. For significant subgingival buildup, a deeper procedure called scaling and root planing may be needed. This involves cleaning the root surfaces below the gumline and smoothing them so gums can reattach more easily. It’s typically done with local anesthesia and may take more than one visit.
You may have seen metal dental scalers sold online for home use. Using these tools yourself carries real risks: you can scratch your enamel (causing tooth sensitivity), damage your gum tissue (leading to gum recession), injure your cheeks or tongue, or accidentally push tartar beneath the gumline, which can cause gum abscesses. Dental professionals train for years to use these instruments safely, and the few dollars saved aren’t worth the potential complications.
Preventing Tartar From Forming
Since tartar is just mineralized plaque, the key is removing plaque before it hardens. Brushing twice a day and flossing daily are the foundation. Pay extra attention to the areas where tartar tends to accumulate first: the inside of your lower front teeth and the outside of your upper molars, both near salivary gland openings where mineral-rich saliva flows most heavily.
Tartar-control toothpastes contain ingredients called pyrophosphates that work by binding to calcium ions in your saliva before they can deposit onto plaque. This blocks the crystal growth that turns soft plaque into hard calculus. These toothpastes are effective at slowing new tartar formation above the gumline, but they won’t remove tartar that already exists.
Even with excellent home care, most people develop some tartar over time. Regular dental cleanings, typically every six months, catch buildup before it progresses to the point where it’s causing gum damage. If you’re someone who forms tartar quickly, your dentist may recommend cleanings every three to four months instead.