Periodontitis: stages, grades and links with general health
- Oral pathology
Periodontitis destroys the gum attachment and bone around teeth. It is staged by severity and graded by speed, and it worsens and is worsened by diabetes.
See it in 3D: Gums (gingiva) · Mandible · Maxillae
What it is
Periodontitis is chronic inflammation, triggered by a dysbiotic biofilm, that destroys the periodontal ligament and alveolar bone. It causes receding or swollen gums, pockets, bad breath, drifting and loosening of teeth, and eventually tooth loss. Severe periodontitis affects roughly one adult in five worldwide. The 2017 international classification describes it by stage (I to IV, by attachment and bone loss, tooth loss and complexity) and grade (A, B or C, by rate of progression and risk factors such as smoking and diabetes).
How to recognise it
- Stage I–II: mild to moderate attachment loss; Stage III–IV: severe, with tooth loss and complex treatment.
- Grade C (rapid progression): heavy smoking, poorly controlled diabetes or destruction out of proportion to plaque.
- Smoking is the strongest modifiable risk factor and hides bleeding.
- Poor glycaemic control worsens periodontitis, and treating periodontitis modestly improves glycaemic control.
- Associated with cardiovascular disease, adverse pregnancy outcomes and aspiration pneumonia; causality is not proven for all.
Differential and risks
- Loose teeth, drifting front teeth and pus from gums in an adult point to advanced periodontitis.
- Severe periodontitis in an adolescent or young adult needs a search for immune defects and diabetes.
- Treatment is mechanical (scaling and root planing) plus control of risk factors; antibiotics are adjuncts in selected cases only.
Next step / Initial management
- Ask every person with diabetes about bleeding or loose teeth and refer for periodontal assessment.
- Severe or rapid periodontitis without known cause: screen for diabetes (glucose or HbA1c) and consider immune disorders.
- Support smoking cessation; refer to the dentist or periodontist for treatment and regular maintenance.
Test yourself
Think of the answer, then tap the question to see it.
What do stage and grade describe in the 2017 periodontitis classification?
Stage describes severity and complexity; grade describes the rate of progression and risk factors.
How are diabetes and periodontitis related?
Poor glycaemic control worsens periodontitis, and periodontal treatment can modestly improve glycaemic control.
Is antibiotic therapy the main treatment of periodontitis?
No; mechanical biofilm removal and control of risk factors are the basis; antibiotics are adjuncts in selected cases.
Connections
See it in 3D3
The structures of Durgical's 3D anatomy where it is found.
Educational content; it does not replace assessment by a dentist or doctor and is not a clinical instruction. For facial or neck swelling with difficulty swallowing or breathing, a knocked-out tooth or bleeding that will not stop, go to an emergency department at once.
Sources: Periodontitis (StatPearls Publishing (NCBI Bookshelf), 2023); Periodontal Disease (StatPearls Publishing (NCBI Bookshelf), 2025); Periodontal (Gum) Disease (National Institute of Dental and Craniofacial Research (NIDCR, NIH), 2024); Global oral health status report: towards universal health coverage for oral health by 2030 (World Health Organization, 2022).
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Representative model, for educational purposes only.