What do periodontitis stages and grades mean?

Your dentist just used words like “Stage II” or “Grade B” to describe your gum disease. You nodded along, but now you’re wondering what those labels actually mean for your teeth. 

Here’s the short answer: A stage describes the damage periodontitis has caused and how complex it may be to manage. A grade describes how quickly it has progressed or may progress, taking certain risk factors into account. Together, they help your dentist plan care for your situation. 

What you'll learn in this article: 

• How periodontitis stages differ from grades 

• What Stages I–IV and Grades A–C mean 

• How dental records, smoking and diabetes affect the assessment 

• What your diagnosis means for treatment and ongoing care 

Schedule an appointment with an Aspen Dental provider to have your gum measurements explained and talk through your next steps. 

Is gingivitis the first stage of periodontitis? 

Not exactly. Gum inflammation without loss of the attachment and bone that support your teeth can often be reversed with effective daily cleaning and professional care.¹ Staging describes the tissue damage that periodontitis has already caused, so it applies once that loss has occurred, and the earlier inflammation isn’t staged.² Periodontitis involves damage to the tissues supporting teeth and needs ongoing management.¹ 

Bleeding or redness alone doesn't tell you which condition you have. Your dentist checks the gums and supporting structures before assigning a periodontitis stage and grade. 

What are the four stages of periodontitis? 

Staging considers attachment loss, bone loss and the complexity of care. Attachment loss means a tooth has lost some of the tissue support that anchors it. Teeth lost because of periodontitis also count; teeth missing for unrelated reasons don't count toward that tooth-loss criterion.²

Stage I: Mild periodontitis 

There is a small amount of attachment and bone loss, with no teeth lost to periodontitis. The damage is less extensive than in later stages, but treatment still matters.²

Stage II: Moderate periodontitis 

Attachment and bone loss are greater than in Stage I, but there is still no tooth loss due to periodontitis. Treatment aims to control further damage.²

Stage III: Severe periodontitis 

Significant support has been lost, and treatment may be complicated by deep pockets or damage around the area where a tooth's roots divide. Up to four teeth may have been lost to periodontitis, although tooth loss isn't required for Stage III.²

Stage IV: Very severe periodontitis 

Stage IV adds concerns such as difficulty chewing, bite collapse, drifting teeth or the need for extensive dental work to rebuild how your teeth fit together. Losing five or more teeth to periodontitis can also place a case here. Your care team assesses the whole picture rather than counting missing teeth alone.² 

An advanced stage doesn't mean every tooth must be removed. It helps explain why coordinated care, sometimes involving more than one specialist, may be needed.³

What do periodontitis Grades A, B and C mean? 

Grades describe progression rather than the amount of damage alone. Your dentist uses evidence about how the disease has behaved and factors that may affect its future course. 

• Grade A: Evidence suggests slow progression. 

• Grade B: Evidence suggests a moderate rate of progression. 

• Grade C: Evidence suggests rapid progression or risk factors that warrant a higher grade.²

Grade A isn't a guarantee that the disease will stay stable, and Grade C doesn't mean tooth loss is certain. The grade helps your care team plan treatment and follow-up.³ 

How do smoking and diabetes affect the grade? 

Smoking and diabetes control are grading considerations. The assessment includes how much someone smokes and, for people with diabetes, their blood sugar control. The classification provides specific thresholds, which clinicians consider alongside evidence of progression and their clinical judgment.²^,³

Share your smoking history and, if you have diabetes, your most recent hemoglobin A1c results, a blood sugar measure. Your dentist may coordinate with your medical provider or discuss support for quitting smoking as part of your periodontal care.³ 

How does your dentist determine your stage and grade? 

Your dentist or hygienist measures the pockets around your teeth, checks attachment levels and examines the gums. X-rays help show bone loss. They also review loose or missing teeth and your medical history.¹

Previous records are especially useful for grading because they can show changes over time. Without older records, your dentist can use indirect evidence, including the amount of bone loss relative to your age. Your stage reflects the area with the greatest loss, so measurements across your whole mouth matter.²^,³

What do stage and grade mean for treatment? 

Two people at the same stage may need different care.³ Treatment can include scaling and root planing, which cleans tooth-root surfaces below the gumline. If nonsurgical care isn't enough, periodontal surgery may be recommended.⁴

After active treatment, ongoing periodontal maintenance helps sustain gum health. Your provider will recommend a schedule based on your condition and response to treatment. Feeling better doesn't mean follow-up is no longer needed.³^,⁴

To understand your diagnosis and care options, schedule an examination with your local dental provider. 

What do periodontitis stages and grades mean? FAQs 

Does successful treatment reset my stage? 

Usually not. A treated patient may be described as stable while retaining the original stage. Selected cases involving successful regeneration of supporting tissues may be reassessed differently, but routine improvement doesn't automatically lower the stage.³

Does the stage apply to every tooth? 

It is a whole-mouth classification influenced by the most severely affected areas and treatment complexity. That doesn't mean all teeth have equal damage. Your diagnosis may also describe how widely the disease is distributed.³

Can my grade change over time? 

Your grade rests on evidence of how the disease has progressed and on risk factors such as smoking and diabetes. Improved blood sugar control or stopping smoking is helpful, but neither automatically lowers a grade, because the history and your dentist’s overall assessment still matter.²^,³ 

What records should I bring if I'm switching dentists? 

Ask your previous office to send older X-rays, periodontal measurements and treatment notes. Bring a medication list and mention changes in your health. These details help the new team assess your condition and continue your care. 

Sources 

¹ National Institute of Dental and Craniofacial Research: “Periodontal (Gum) Disease.” https://www.nidcr.nih.gov/health-info/gum-disease 

² American Academy of Periodontology: “Staging and Grading Periodontitis.” https://www.perio.org/wp-content/uploads/2019/08/Staging-and-Grading-Periodontitis.pdf 

³ American Academy of Periodontology: “Frequently Asked Questions on the 2018 Classification of Periodontal and Peri-Implant Diseases and Conditions.” https://www.perio.org/wp-content/uploads/2019/08/2017-World-Workshop-on-Disease-Classification-FAQs.pdf 

⁴ American Academy of Periodontology: “Non-Surgical Treatments.” https://www.perio.org/for-patients/periodontal-treatments-and-procedures/non-surgical-treatments/