The 4 Stages of Gum Disease: From Gingivitis to Periodontitis

A little pink in the sink after flossing is easy to ignore. Yet bleeding gums are often the first sign of gum disease, which tends to develop slowly and quietly, usually without pain.

Gum disease moves through stages, and the earliest one can usually be reversed. Below, we walk through the four stages, explain the difference between gingivitis and periodontitis, and answer the question patients in our London, Ontario office ask most often: can gum disease be reversed?

Key Takeaways

• Gum disease usually progresses in four stages: gingivitis, early periodontitis, moderate periodontitis, and advanced periodontitis.
• Gingivitis affects only the gums and can usually be reversed. Periodontitis damages bone, which usually cannot be fully restored, but the disease can often be controlled.
• Early gum disease often causes no pain, so routine exams are one of the most reliable ways to catch it.

What Is Gum Disease?

Gum disease, also called periodontal disease, is inflammation and infection of the tissues that support your teeth: the gums, the ligaments that anchor each tooth, and the jawbone underneath.

It starts with plaque, the sticky film of bacteria that forms on teeth every day. If plaque is not cleaned away, it hardens into tartar. The Canadian Dental Association notes that tartar cannot be removed by brushing and flossing and can lead to infection where the gums attach to the teeth. Research also links gum disease with conditions such as diabetes and heart disease, though a link does not prove cause.

The 4 Stages of Gum Disease

Patient resources such as Cleveland Clinic’s guide to periodontal disease describe gum disease in four stages.

Stage 1: Gingivitis

Gingivitis is inflammation limited to the gums, with no bone loss. Healthy gums fit snugly around each tooth, leaving a shallow space of roughly 1 to 3 millimetres. With gingivitis, gums may look red and puffy and bleed when you brush or floss, but they stay attached to the tooth. Many people notice nothing, and smoking can reduce bleeding, hiding this early sign.

Stage 2: Early Periodontitis

Bacteria move below the gumline, and the gums begin to separate from the teeth, forming periodontal pockets, often around 4 millimetres deep. Plaque collects where brushing and flossing cannot reach, and the bone starts to break down. Many people still feel no pain.

Stage 3: Moderate Periodontitis

More ligament, soft tissue, and bone break down, and pockets often deepen to around 5 millimetres. You may notice receding gums that make teeth look longer, sensitivity to hot or cold, persistent bad breath, pus along the gumline, or tenderness when chewing.

Stage 4: Advanced Periodontitis

Bone loss is significant and pockets are often 6 millimetres or deeper. Teeth may loosen or shift, your bite can change, and painful gum infections (abscesses) become more likely. The Canadian Dental Association identifies gum disease as one of the main reasons adults lose their teeth.

These measurements are a general guide, not a diagnosis. Your dentist also considers bone levels on X-rays, gum recession, and how firmly each tooth is held in place.

How Dentists Stage Gum Disease Today

Dentists also use a more detailed framework, published in the Journal of Periodontology in 2018, that sorts periodontitis into Stages I to IV by severity and adds a grade (A, B, or C) for how fast it appears to be progressing. Smoking and diabetes can raise the grade. Two people with “moderate” gum disease may be losing ground at very different speeds, which is why your care plan is built around your mouth, not a chart.

Gingivitis vs Periodontitis: What’s the Difference?

The main difference comes down to one question: has the damage reached the bone and connective tissue that hold your teeth in place?

Not every case of gingivitis progresses. Genetics, smoking, diabetes, and stress all affect whether it does, and how quickly.

Can Gum Disease Be Reversed?

It depends on the stage.

Gingivitis: Usually, Yes

Because gingivitis has not damaged the bone, it can usually be reversed. The Canadian Dental Association notes that gum disease can be turned around in its early stages with a professional cleaning to remove tartar, plus brushing twice a day and flossing once a day. Many patients notice less bleeding within a couple of weeks of consistent home care, though every mouth responds differently.

Periodontitis: Controlled, Not Cured

Once bone and gum attachment are lost, the damage usually cannot be fully undone. Cleveland Clinic describes periodontal disease as manageable rather than curable, with treatment able to reduce infection and rebuild some bone and tissue. Think of it less like a cold that clears up and more like blood pressure: something you keep in check with steady care. The sooner treatment starts, the better your chances of keeping your natural teeth.