What Are the Stages of Gum Disease?

Gum disease moves through recognizable stages. It starts as gingivitis, inflammation limited to the gum tissue. Left untreated, it can advance into periodontitis, where the infection spreads to the bone and fibers anchoring your teeth.

Periodontitis is then split into stages I through IV. Each stage describes how far the disease has spread and how much support your teeth have lost, from mild to severe.

Your stage records damage that has already happened, so it isn't lowered after treatment. What treatment changes is whether the disease stays active, though bone already lost usually doesn't return.

What do pocket depth numbers mean?

A pocket is the small gap between your gum and tooth, measured in millimeters with a thin probe. Healthy pockets usually measure 1 to 3 millimeters. Numbers of 4 millimeters or more usually mean the gum has pulled away from the tooth and needs attention.

Deeper numbers generally point to more advanced disease. A pocket of 4 to 5 millimeters often responds well to a deep cleaning. Pockets of 6 millimeters or more sometimes need more advanced treatment to clean and reshape properly.

A full periodontal exam measures every tooth, not just the ones that already bother you. Bleeding when the pocket is probed matters as much as the number itself.

How do periodontists stage and grade gum disease today?

Periodontists now describe periodontitis with a stage and a grade. The stage, I to IV, shows how severe and complex the damage already is. The grade, A to C, estimates how quickly it tends to progress.

Stage I is mild, with bone loss limited to the upper part of the root and no teeth lost to the disease. Stage II is moderate, with somewhat more bone loss but still confined to that upper region.

Stage III is severe: bone loss reaches further down the root, and some teeth may already be missing because of gum disease. Stage IV is the most advanced, often affecting how your teeth bite together and sometimes needing broader rehabilitation.

Grade also weighs risk factors such as smoking or diabetes, which can speed up damage, and how much bone loss you have relative to your age.

The stages of gum disease at a glance
Stage	What is happening	Common signs	Usual first step
Gingivitis	Inflammation limited to the gums; the bone hasn't been affected yet	Red, puffy or bleeding gums	A professional cleaning and better home care
Early periodontitis (stage I)	Bone loss just beginning, limited to the upper part of the root	Mild bleeding; pockets around 4 mm	Scaling and root planing
Moderate (stage II)	Bone loss further along, still confined to the upper root region	Deeper pockets; gums may look puffy or recede slightly	Scaling and root planing, often in sections
Severe or advanced (stages III–IV)	Bone loss reaching the middle or lower root, sometimes with teeth already lost	Loose or shifting teeth, longer-looking teeth, visible gaps	Deep cleaning, often followed by periodontal surgery

Which stages can be reversed, and which can only be controlled?

Gingivitis is the one stage that can be fully reversed, because the bone hasn't been touched yet. Once periodontitis sets in, treatment can control it, but lost bone generally doesn't grow back on its own.

That's true across stages I through IV. Even early periodontitis, once bone is lost, is managed rather than cured, though early treatment usually keeps the damage minor.

The risk of waiting grows with each stage. Pockets deepen, more bone loss from gum disease sets in, and teeth can loosen, drift or need to come out.

What treatment usually fits each stage?

Treatment generally matches the stage you're in. Gingivitis usually needs only a professional cleaning and steadier brushing and flossing at home. Periodontitis at any stage typically starts with a deeper approach.

For early and moderate periodontitis, scaling and root planing is the usual first step: a deep cleaning below the gumline. Many pockets shrink and stop bleeding once it heals.

For stage III or IV, pockets often stay deep after that cleaning. Periodontal surgery may then open the gum so the roots and bone can be cleaned and reshaped directly.

Whatever stage you're in, the full gum disease treatment ladder covers every option in more depth, from the first cleaning to ongoing maintenance.

Care at Perio One

At Perio One, we stage your gum disease with a full periodontal exam before recommending any treatment. Dr. Randal Comeaux, DDS, Diplomate of the American Board of Periodontology, walks you through what your stage means for your teeth.

He explains your stage and grade in plain language, along with the treatment that generally fits it. Referrals from other dentists in the Lafayette area are always welcome.

We also coordinate with your general dentist, and once your stage is under control, our periodontal maintenance program helps keep it that way.

When to call us

Gums that bleed for more than a week or two despite careful brushing
Gums pulling back, or teeth that look longer than they used to
A tooth that feels loose or has shifted position
New spaces opening up between your teeth
Pus or swelling at the gumline

Our periodontists, Dr. Randal Comeaux and Dr. Lauren Langlois, can talk through what you’re noticing.

Call to schedule

What to expect

Exam and staging
We measure the pockets around every tooth and review X-rays to see how much bone has been affected.
Your stage and grade explained
Dr. Comeaux walks you through what stage and grade your gums are in, in plain language.
A plan that fits your stage
Early stages usually start with a deep cleaning; later stages may need more.
Treatment
You receive the recommended care, often over more than one visit.
Recheck
Your pockets are measured again to see how they responded and whether any area needs more care.
Ongoing maintenance
Regular maintenance visits help keep your stage from advancing again.

Common questions

Can stage 3 gum disease be reversed?

No. Stage III periodontitis has already cost some bone support, and lost bone generally doesn't grow back on its own. Treatment can control the infection and help stop it from getting worse, and in some spots part of the lost support may be rebuilt.

What stage of gum disease is irreversible?

Any stage of periodontitis, once bone has been lost, is managed rather than reversed. Only gingivitis, before bone is affected, can fully return to normal with treatment and better home care.

How fast does gum disease progress?

It varies a lot between people. The grade in the current staging system reflects that: grade A tends to move slowly, and grade C more quickly, often in people who smoke or have uncontrolled diabetes.

What stage of gum disease causes loose teeth?

Looseness usually shows up in stage III or IV, once enough bone has been lost around a tooth's roots. It can occasionally appear earlier if the bone loss around one tooth is unusually uneven.

Is stage 2 gum disease bad?

Stage II is moderate periodontitis: real bone loss has occurred, but it's still confined to the upper part of the root. It responds well to treatment, and catching it here usually protects more of your bone and teeth.

Sources

This page is general education, not a diagnosis. Your periodontist will recommend care after an examination.

The stages of gum disease, from gingivitis to periodontitis

At a glance

Your deep cleaning, step by step