Periodontal disease is an infection of the gums and bone that support your teeth. It starts when bacteria build up along the gumline and, left untreated, gradually destroys the tissue and bone holding teeth in place. About 42% of American adults over age 30 have some form of periodontitis, and that number climbs to nearly 60% among adults 65 and older.
The term covers a spectrum, from mild inflammation you can reverse at home to severe bone loss that threatens your entire set of teeth. Understanding where you fall on that spectrum determines what treatment looks like and how much damage can be undone.
How Periodontal Disease Develops
It begins with plaque, a sticky film of bacteria that forms on your teeth every day. When plaque isn’t removed through brushing and flossing, it hardens into tartar (also called calcite), which you can’t brush away on your own. The bacteria in tartar irritate your gums, causing inflammation. At this point, you have gingivitis, the mildest form of gum disease. Your gums may look red, feel puffy, and bleed when you brush or floss.
Gingivitis is fully reversible. With consistent brushing, flossing, and a professional cleaning, your gums can return to normal. But if the inflammation continues unchecked, bacteria work their way below the gumline and begin attacking the connective tissue and bone that anchor your teeth. That transition from gingivitis to periodontitis is the critical turning point, because bone loss from periodontitis cannot naturally regenerate. Treatment can stop the disease and stabilize what’s left, but it can’t fully restore what’s already gone.
Stages of Periodontitis
Dentists classify periodontitis into four stages based on how much attachment and bone have been lost, how deep the pockets around your teeth measure, and how many teeth are affected.
In a healthy mouth, the small gap between your gum and tooth measures 1 to 3 millimeters. Pockets deeper than 4 millimeters signal trouble, and anything beyond 5 millimeters is difficult to clean without professional help.
- Stage I (initial): Mild attachment loss of 1 to 2 millimeters. Bone loss is minimal, limited to the upper portion of the tooth root. Pocket depths stay at 4 millimeters or less. No teeth have been lost.
- Stage II (moderate): Attachment loss of 3 to 4 millimeters with bone loss up to about a third of the root length. Pockets reach up to 5 millimeters. Bone loss is still mostly horizontal, meaning it recedes evenly rather than creating deep craters.
- Stage III (severe): Attachment loss of 5 millimeters or more, with bone destruction extending into the middle third of the root and beyond. Pockets reach 6 millimeters or deeper. Vertical bone defects, where bone erodes unevenly around a tooth, begin to appear. Five or more teeth may already be lost.
- Stage IV (advanced severe): Same level of bone and attachment loss as Stage III, but with additional complications: teeth shifting or drifting, bite collapse, significant tooth mobility, and fewer than 20 remaining teeth. At this point the disease threatens the entire set of teeth and often requires complex rebuilding.
Each stage can also be described as localized (fewer than 30% of teeth involved), generalized, or following a molar/incisor pattern where the disease clusters around specific teeth.
Risk Factors
Smoking is one of the strongest risk factors. Smokers face twice the risk of gum disease compared to nonsmokers, and the risk increases with the number of cigarettes smoked and the years spent smoking. All forms of tobacco, including pipes and smokeless tobacco, raise the risk. Smoking also makes treatment less effective because it impairs blood flow to the gums, slowing healing.
Diabetes is closely linked to periodontal disease. People with diabetes are more susceptible to infections in general, and periodontitis is considered a complication of the condition. The relationship goes both ways: gum disease can make blood sugar harder to control, which in turn increases the risk of diabetic complications. Poorly controlled diabetes amplifies the risk significantly.
Other notable risk factors include genetics (some people are simply more prone to aggressive gum disease), hormonal changes during pregnancy or menopause, medications that reduce saliva flow, and conditions that suppress the immune system.
Signs You Might Notice
Periodontal disease is often painless in its early stages, which is why it can progress for years without being detected. The most common early signs are gums that bleed during brushing or flossing, persistent bad breath, and gums that look red or swollen rather than firm and pink.
As the disease advances, you may notice your gums pulling away from your teeth, making teeth look longer. Teeth may feel loose or shift position. You might develop sensitivity to hot or cold foods as roots become exposed. Chewing may become uncomfortable, and you may notice changes in how your bite fits together. By the time teeth feel loose, significant bone loss has already occurred.
Non-Surgical Treatment
The first line of treatment for mild to moderate periodontal disease is a deep cleaning called scaling and root planing. Unlike a standard cleaning, this procedure goes below the gumline. Your dentist or hygienist numbs the area with local anesthesia, then uses hand instruments or ultrasonic tools to remove plaque and tartar from both the tooth surface and the root underneath the gum. After scaling, they smooth the root surfaces, which helps gums reattach to the tooth and makes it harder for bacteria to gain a foothold.
The procedure is typically done in sections over two or more appointments. Your dentist may also place antibiotics directly around the tooth roots or prescribe oral antibiotics to help control infection afterward. Gums are usually tender for a few days following treatment, and some sensitivity is normal as they heal and tighten around the teeth.
Surgical Options for Advanced Disease
When pockets remain deep after scaling and root planing, or when bone damage is extensive, surgery becomes necessary. The most common procedure is osseous surgery, also called pocket reduction surgery. A periodontist makes small incisions to fold back the gum tissue, cleans out bacteria and infected tissue from around the roots, and reshapes the underlying bone to eliminate the deep pockets where bacteria thrive. The gums are then stitched back into place.
A newer approach uses laser energy to target and destroy bacteria while preserving healthy tissue, avoiding the need for incisions and stitches. Results with laser treatment are mixed, however, and it isn’t appropriate for every case. In areas where bone has been severely damaged, grafting procedures can rebuild some of the lost structure. Your periodontist may place bone graft material into the defect and use barrier membranes to guide the growth of new bone and tissue.
Links to Other Health Conditions
Periodontal disease doesn’t stay in your mouth. The chronic inflammation and bacteria involved have been linked to several serious conditions elsewhere in the body. Several studies have shown that gum disease may increase the risk of heart disease, likely because the inflammatory molecules produced in diseased gums enter the bloodstream and contribute to arterial inflammation.
Bacteria from periodontal infections can also be inhaled into the lungs, contributing to respiratory conditions like pneumonia. Research has found that men with gum disease were 49% more likely to develop kidney cancer, 54% more likely to develop pancreatic cancer, and 30% more likely to develop blood cancers. Scientists have also identified a connection between the bacteria involved in gum disease and the progression of Alzheimer’s disease, with evidence suggesting these bacteria can travel to the brain.
These links don’t mean gum disease directly causes these conditions, but they reinforce that treating periodontal disease has benefits well beyond keeping your teeth.
Long-Term Maintenance
Periodontal disease can be treated and controlled, but it can’t be completely eradicated. Once you’ve had active treatment, you’ll need ongoing maintenance visits that go beyond a standard twice-yearly cleaning. For people with Stage III or Stage IV disease, maintenance appointments are typically scheduled every 3 to 4 months for the rest of the time you have your natural teeth.
If you respond well to treatment, maintain good home care, and don’t have additional risk factors like smoking or diabetes, your periodontist may extend the interval to every 6 to 12 months. On the other hand, if you heal slowly or continue smoking, you may need appointments as often as every 2 months until things stabilize. These maintenance visits include measuring pocket depths, removing any new buildup below the gumline, and checking for signs of disease progression. Skipping them is one of the fastest ways to lose ground.