Periodontal disease is a chronic infection of the gums and bone that support your teeth. It affects about 42% of U.S. adults aged 30 and older, making it one of the most common conditions dentists treat. Most cases are mild or moderate, but roughly 8% of adults have the severe form, which can lead to loose teeth and tooth loss if untreated.
How It Starts and Progresses
Your mouth naturally contains hundreds of bacterial species that form a thin film on your teeth called biofilm, or plaque. In a healthy mouth, these bacteria coexist with your immune system without causing problems. Periodontal disease begins when the bacterial community shifts out of balance. Certain harmful bacteria, even in small numbers, can reshape the behavior of the entire bacterial community, making it more aggressive overall. This shifted community is what triggers the disease process.
When your immune system detects these harmful bacteria, it sends white blood cells to the gum tissue to fight them off. These immune cells use a range of weapons: they engulf bacteria, release enzymes, and produce reactive molecules to kill invaders. The problem is that these same weapons also damage your own tissue. Your body releases inflammatory signaling molecules that recruit even more immune cells, creating a self-reinforcing loop of inflammation. Over time, this sustained immune response breaks down the connective tissue and bone that hold your teeth in place.
The bone loss happens through a specific process. Inflammatory signals trigger the formation of specialized cells that dissolve bone. In healthy conditions, your body balances bone breakdown with bone rebuilding. In periodontal disease, that balance tips heavily toward destruction. The soft tissue fibers connecting your teeth to the bone are also broken down by enzymes released from both immune cells and the tissue’s own cells. This is why periodontitis, once it reaches the bone, is not fully reversible. The damage is structural.
Gingivitis vs. Periodontitis
Periodontal disease exists on a spectrum. The earliest form, gingivitis, affects only the gum tissue. Your gums become red, swollen, and bleed easily when you brush or floss. At this stage, no bone loss has occurred, and the condition is completely reversible with improved oral hygiene and professional cleaning.
Periodontitis is the more advanced form. It means the infection has spread below the gumline and started destroying the bone and connective tissue. Unlike gingivitis, periodontitis cannot be fully reversed, only managed. Left untreated, it progresses through stages of increasing bone loss, deeper pockets between the teeth and gums, gum recession, shifting or loosening of teeth, and changes in how your bite fits together. In severe cases, teeth may need to be extracted.
Warning Signs to Recognize
The tricky part of periodontal disease is that it’s often painless until it’s fairly advanced. Many people don’t realize they have it. The earliest and most common sign is bleeding gums, particularly when brushing, flossing, or eating hard foods. Healthy gums don’t bleed.
As the disease progresses, you may notice:
- Persistent bad breath that doesn’t go away with brushing
- Gums pulling away from your teeth, making them look longer
- Teeth that feel loose or shift position over time
- Changes in your bite, where your teeth no longer line up the way they used to
- Pus between teeth and gums
- Pain when chewing
Any of these signs, especially in combination, suggest the disease has moved beyond gingivitis.
Who Is Most at Risk
Smoking is the single strongest modifiable risk factor. Smokers have an 85% higher incidence of periodontitis compared to non-smokers. Smoking also reduces blood flow to the gums, which impairs healing and makes treatment less effective.
Diabetes is the other major risk factor, and the relationship goes both ways. Poorly controlled blood sugar fuels gum inflammation, and periodontal disease makes blood sugar harder to control. The two conditions share overlapping inflammatory pathways and oxidative stress, which is why managing one often helps the other. Additional risk factors include genetics, hormonal changes (such as during pregnancy), certain medications that cause dry mouth, and conditions that suppress the immune system.
How Dentists Diagnose It
During a dental exam, your dentist or hygienist uses a small probe to measure the depth of the space between each tooth and the surrounding gum tissue. These measurements, taken in millimeters, are the primary diagnostic tool. Pockets of 3 mm or less are consistent with health. A reading of 4 mm falls in a gray zone between health and disease. Pockets of 5 mm or deeper indicate attachment loss and active disease.
Your dentist will also take X-rays to evaluate bone levels. On a dental X-ray, a gap greater than about 2 mm between the point where the tooth’s enamel ends and the top of the bone suggests significant bone loss. Together, pocket depth measurements, X-rays, and a visual exam of gum tissue determine how far the disease has progressed.
Treatment for Early to Moderate Disease
The first-line treatment for periodontitis is a deep cleaning procedure called scaling and root planing. It goes further than a routine cleaning. Scaling removes plaque and hardite deposits (tarite) both above and below the gumline. Root planing smooths the root surfaces of your teeth, which helps gums reattach and makes it harder for bacteria to cling to the roots.
The procedure is typically done under local anesthesia and may be split across two or more visits, treating one section of the mouth at a time. Most people return to normal activities the same day. Your gums may feel sore for a couple of days afterward, and your teeth might feel slightly sensitive for a month or two as the gums heal and tighten. Some temporary looseness of the teeth is also normal and resolves as the tissue firms up.
After initial treatment, your dentist reassesses the pocket depths. Sites that have improved to 5 mm or less can typically be maintained without surgery.
When Surgery Becomes Necessary
If pocket depths remain at 6 mm or more after scaling and root planing, surgical options are usually considered. The most common is flap surgery, where the gum tissue is lifted back so the dentist can access and clean the root surfaces and bone underneath directly, then reposition the tissue to fit more snugly around the teeth.
For certain patterns of bone loss, bone grafts or tissue-regeneration procedures may be used to rebuild some of the lost support. Deep, narrow bone defects (greater than 3 mm) typically respond better to regenerative techniques than to reshaping alone. The goal of any surgical approach is to reduce pocket depths to a level where you and your dental team can keep them clean long-term.
Ongoing Maintenance After Treatment
Periodontal disease is a chronic condition. Even after successful treatment, you’ll need more frequent professional cleanings than the standard twice-a-year schedule. The American Academy of Periodontology recommends that most patients with a history of periodontitis start with cleanings every three months. This frequency significantly reduces the likelihood of the disease progressing compared to less frequent visits.
That said, the ideal interval varies from person to person. Some patients eventually extend to every four or six months, while others need to stay on a three-month cycle indefinitely. Your dentist will adjust the schedule based on how your gums respond. At home, thorough daily brushing and flossing remain the foundation of keeping the disease in check.
The Link to Heart Disease and Diabetes
Periodontal disease doesn’t stay contained to your mouth. When the gum tissue lining becomes damaged, bacteria and their toxic byproducts enter the bloodstream. This triggers a systemic inflammatory response that can affect organs far from the mouth.
In the cardiovascular system, periodontal bacteria can directly damage blood vessel walls. They promote the production of molecules that make blood vessel linings sticky, attracting immune cells and contributing to plaque buildup inside arteries. These bacteria also trigger the release of a potent blood vessel-constricting molecule, and they activate clotting factors that promote blood clot formation. People with periodontitis consistently show elevated blood levels of C-reactive protein, a marker of systemic inflammation that independently predicts cardiovascular events.
The connection to diabetes centers on shared inflammatory chemistry. The same inflammatory molecules elevated in periodontal disease interfere with insulin signaling, making blood sugar regulation harder. Treating periodontal disease in diabetic patients has been shown to improve blood sugar control, reinforcing that these conditions actively feed each other. Oxidative stress, a type of cellular damage caused by an imbalance of harmful reactive molecules, is another shared driver of both conditions.