The short answer
Plaque is a sticky, colorless film of bacteria that starts forming on your teeth within minutes after eating. You can remove it with brushing and cleaning between your teeth. Tartar, also called calculus, is plaque that was left in place and hardened. Once it hardens, brushing cannot remove it; only a dentist or hygienist can. Both irritate the gums, and tartar gives new plaque a rough surface to cling to.
General information, not a diagnosis. Your dentist will examine your mouth before recommending treatment.
What plaque is
Run your tongue over your teeth a few hours after brushing and you can feel it: a slightly fuzzy coating. That is plaque, a sticky, colorless film of bacteria that lives on tooth surfaces. The NIH's dental institute describes it as hard to see, which is why it is easy to miss near the gumline and between the teeth.
Plaque is not dirt. It is a living layer. When you eat or drink something with sugar or starch, the bacteria in plaque release acids that attack the enamel. Repeated attacks pull minerals out of the enamel faster than saliva can put them back, and that is how a cavity starts.
MedlinePlus notes that plaque begins to build up on teeth within a few minutes after eating. That is the whole reason daily cleaning matters: you are not removing a day's worth of buildup, you are interrupting a process that does not stop.
How plaque turns into tartar
Plaque that is not removed with thorough daily brushing and cleaning between the teeth can eventually harden into calculus, the dental term for tartar. The change is physical: the soft film becomes a hard deposit that is stuck to the tooth.
Tartar collects where plaque sits longest: at the base of the teeth along the gumline, between the teeth, and below the gumline where the brush does not reach. The NIH points out that some plaque can harden below the gum line and irritate the gums without ever being visible.
Once tartar forms, it makes the tooth surface rough. The ADA's MouthHealthy page on plaque puts it plainly: tartar makes it more difficult to keep your teeth clean. New plaque sticks to tartar more easily than to smooth enamel, so buildup tends to speed up rather than level off.
Why you cannot brush tartar off
This is the part people find frustrating. You can brush harder, floss more, and buy a tartar-control toothpaste, and the deposit that is already there stays. The NIH states it directly: the only way to remove tartar is to have your teeth cleaned by a dentist or dental hygienist. MedlinePlus says the same: only a professional dental scaling can remove it.
Good technique and daily cleaning between the teeth help prevent new tartar from forming. They do not remove existing deposits, and nothing you do at home reaches the tartar that has formed below the gumline.
So the division of labor is simple. You remove plaque every day. The hygienist removes tartar at your cleaning and exam visits, on a schedule that follows your risk.
| Plaque | Tartar (calculus) | |
|---|---|---|
| What it is | A soft, sticky, colorless film of bacteria | Plaque that has hardened into a mineral deposit |
| How it forms | Begins building within minutes after eating | Forms when plaque is left in place long enough to harden |
| Can you see it | Hard to see; a disclosing dye shows where it is | May be visible at the gumline or hidden below it |
| Who removes it | You, with daily brushing and cleaning between teeth | Only a dentist or hygienist, with a professional cleaning |
| What it leads to | Cavities and gum inflammation if it stays | Gingivitis that can progress to periodontitis |
What tartar does to your gums
Plaque and tartar both contain bacteria that can trigger inflammation in the gums and the tissues that support the teeth. When tartar collects along the gumline, the gum tissue can become swollen and may bleed easily. That is gingivitis, the early stage of gum disease.
Gingivitis is usually reversible with a professional cleaning and daily brushing and cleaning between the teeth. If the tartar is not removed, the NIH warns that gingivitis can get worse and lead to periodontitis, the stage where the gums pull away from the teeth, pockets form, and the bone that holds the teeth begins to break down. The CDC notes that gum disease can often become serious before a person notices symptoms.
Bleeding when you brush or floss is the sign most people notice first, and it is not a sign you are brushing too hard. The practice's page on why gums bleed covers what to do about it, and the blog post on early signs of gum disease lists the other warning signs.
What the hygienist removes, and how
At a routine cleaning, the hygienist uses hand instruments and often an ultrasonic scaler to remove plaque and tartar from the tooth surfaces above and just below the gumline, then polishes the teeth. The dentist examines the gums and may take X-rays when your history and risk call for them, because X-rays show the bone level that a visual exam cannot.
If tartar has built up on the root surfaces inside periodontal pockets, a routine cleaning cannot reach it. That is when a deep cleaning, called scaling and root planing, is recommended. The guide on deep cleaning vs. regular cleaning explains how your dentist decides between the two.
If you have not had a cleaning in years, expect the first visit to take longer and to involve more scraping than you remember. Some tenderness afterward is common. MedlinePlus notes that bleeding and tenderness from gingivitis should lessen within one or two weeks after a professional cleaning, as long as home care continues.
Keeping plaque from hardening again
Tartar is a plaque problem that went on too long. These habits keep the soft film from getting the time it needs to harden. The practice's oral hygiene basics page shows the technique.
- Brush twice a day with a fluoride toothpaste, angling the bristles toward the gumline where plaque collects.
- Clean between your teeth once a day with floss or an interdental cleaner. The ADA notes this removes the film along the gumline before it can harden. If you are not sure it matters, read Do You Really Need to Floss Every Day?
- Limit snacking and sipping sugary drinks between meals, since each exposure restarts the acid attack.
- If you cannot tell where you are missing, plaque-disclosing tablets or rinses stain the plaque so you can see it and brush those spots again.
- Keep your checkups and cleanings. The interval depends on your risk; people with a history of gum disease or diabetes may be asked to come more often.