Conditions

Periodontitis

Evidence: High Conditions Reading time: approx. 5 min. Reviewed: 11.08.2026 · KEERN Editorial Team

Periodontitis is a chronic, multifactorial inflammatory disease of the tooth-supporting structures, marked by clinical attachment loss and progressive destruction of periodontal tissue, including the alveolar bone. Under current classification, a case is defined by interdental attachment loss at two or more non-adjacent teeth, or buccal or oral attachment loss of at least 3 millimeters with probing depths over 3 millimeters at two or more teeth. This loss generally cannot be fully reversed.

Related terms:GingivitisPlaqueBiofilmCariesInterdental spaceInterdental brush

Definition

Periodontitis is a chronic, multifactorial inflammatory disease of the tooth-supporting structures. Unlike gingivitis, the inflammation here does not stay confined to the gums. It also involves the periodontal ligament and, as it progresses, the jawbone. The resulting tissue loss generally cannot be fully reversed.

Periodontitis develops in connection with dysbiotic dental biofilms and a dysregulated inflammatory response of the host tissue. Whether and how quickly periodontal tissue is destroyed is further shaped by individual risk and protective factors.

In short

Periodontitis is a serious condition that often progresses for years without pain or obvious symptoms. Unlike gingivitis, tissue loss that has already occurred generally cannot be fully reversed. With proper treatment and consistent supportive care, however, the disease can often be stabilized and the risk of further progression substantially reduced.

Common misconception

Periodontitis is often assumed to announce itself clearly, through pain or obvious discomfort. It usually does not. Many cases progress for years with few noticeable symptoms, which is precisely why regular dental checkups matter more than waiting for something to hurt.

The difference from gingivitis

Both conditions fall within the spectrum of periodontal disease, but they are distinct diagnoses. Gingivitis affects only the gums. Periodontitis is diagnosed once characteristic clinical attachment loss is detectable at multiple teeth and other causes of that tissue loss have been ruled out.

An important point for classification: even after successful periodontitis treatment, the periodontitis diagnosis remains on record, as a stable or remission case. A new episode of gum inflammation in these patients is therefore classified differently than gingivitis in someone with no history of periodontitis.

Stages and grades

Current professional classification, developed jointly by the American Academy of Periodontology and the European Federation of Periodontology, divides periodontitis into four stages (I through IV) describing severity and complexity, from limited early tissue loss to extensive loss with possible tooth loss. Grading (A through C) separately estimates the likely rate of progression; smoking and blood sugar control in diabetes serve as important grade modifiers.

This system helps tailor treatment and follow-up to the individual situation and is applied exclusively by dental professionals.

Risk factors

  • Smoking: one of the most significant modifiable risk factors, for both onset and progression
  • Diabetes: associated with elevated risk and a less favorable course of periodontitis; conversely, periodontitis in people with diabetes is associated with poorer blood sugar control, and successful periodontal therapy can improve this to a limited extent
  • Individual susceptibility, including genetic and immunological factors: influences disease risk but does not, on its own, reliably predict an individual's course
  • Insufficient biofilm control over an extended period

Why symptoms are often absent

Bleeding gums are often one of the earliest warning signs, yet frequently not taken seriously. Many cases also remain painless and low in symptoms for a long time, a key reason periodontitis is often detected late. Regular dental checkups that include probing depth measurements matter more than waiting for noticeable discomfort.

Treatment

Treatment follows a stepped approach. The initial focus is on behavior change and controlling biofilm and risk factors. Bacterial deposits and mineralized buildup are then professionally removed from periodontal pockets, a process known clinically as subgingival instrumentation. Daily biofilm control remains essential but cannot adequately reach deeper pockets, which require professional care.

In selected cases, surgical treatment may be necessary. For certain defects, regenerative procedures can allow partial restoration of periodontal structures.

After active treatment concludes, long-term, generally lifelong supportive periodontal therapy is required. Maintenance visits are adjusted to the individual's risk profile rather than following the same schedule for everyone. Periodontitis is highly treatable, though not in the sense of a one-time cure. It is better understood as a condition managed over the long term.

Key takeaways

  • Periodontitis is present once characteristic loss of supporting tissue is detectable at multiple teeth
  • This tissue loss generally cannot be fully reversed, though the condition can often be stabilized
  • Four stages (severity) and three grades (rate of progression) allow individualized classification
  • Smoking and diabetes rank among the most important modifiable risk factors
  • Often painless for a long time: regular checkups are essential
  • Treatment is stepped and requires lifelong follow-up, not a one-time cure

Frequently Asked Questions

Can periodontitis be painless?

Yes. Many cases remain low in symptoms for a long time, which is why regular dental checkups matter more than waiting for noticeable discomfort.

Is brushing alone enough?

It is necessary but generally not sufficient once periodontitis is present. Deeper periodontal pockets require professional diagnostic and therapeutic care that only a dentist can provide.

What is the difference between gingivitis and periodontitis?

Gingivitis affects only the gums and is reversible. Periodontitis is present once supporting tissue has also been lost, a state that generally cannot be fully reversed. Only a dental examination can reliably tell the two apart.

Can you keep your teeth if you have periodontitis?

Yes, in many cases, especially when the disease is diagnosed and treated early. Consistent treatment and long-term supportive care can often prevent or significantly delay tooth loss, even though tissue already lost is not restored.

Can periodontitis be cured?

With consistent treatment and long-term follow-up, the disease can often be stabilized. Already-lost supporting tissue is not fully restored by this, though in selected cases regenerative procedures can achieve partial restoration.

What does diabetes have to do with periodontitis?

Diabetes can unfavorably affect the risk and course of periodontitis. At the same time, untreated or unstable periodontitis in people with diabetes is linked to poorer blood sugar control. Good medical and dental care should take both conditions into account together.

How common is periodontitis worldwide?

Very common. Global Burden of Disease 2021 data estimate that approximately 12.5 percent of the world's population has severe periodontitis, making it one of the most widespread chronic inflammatory conditions.

KEERN Perspective

Periodontitis shows why long-term oral health cannot rest on any single measure. Daily biofilm control, individual risk factors, professional treatment, and structured follow-up all have to work together.

Daily oral care is one important part of long-term periodontal health, but it is never the whole picture. Diagnosis, treatment, and supportive care belong with a dentist or periodontist.

Professional perspective

Clinical relevance

  • Diagnosis according to current case criteria, including staging and grading
  • Risk factor and systemic disease screening (smoking, diabetes)
  • Stepped treatment planning per EFP S3 guidelines (stage I to III and stage IV)
  • Long-term supportive periodontal therapy (recall intervals based on individual risk)

Diagnosis and case definition

Under the classification from the 2017 World Workshop, co-presented by the American Academy of Periodontology and the European Federation of Periodontology, a periodontitis case is present when interdental clinical attachment loss is detectable at two or more non-adjacent teeth, or when buccal or oral attachment loss of at least 3 millimeters with probing depths over 3 millimeters is present at two or more teeth. Non-periodontitis causes of attachment loss, such as cervical restorations or caries, or root fractures, must be excluded first.

Staging and grading

Staging (Stage I to IV) describes severity and complexity based on attachment loss, radiographic bone loss, tooth loss attributable to periodontitis, and additional complexity factors. Grading (Grade A to C) estimates the rate of progression from direct or indirect evidence; smoking and glycemic control in diabetes serve as important grade modifiers. A 2019 corrigendum corrected specific values in the appendix tables used for applying staging and grading in practice; the underlying case criteria are unaffected. Full reproduction of the staging and grading tables is beyond the scope of this article; for clinical application, the original publication and its corrigendum are the reference.

Clinical implications

Smoking and diabetes are considered the best-documented modifying risk factors for periodontitis onset and progression and are explicitly incorporated into grading. The relationship with diabetes is bidirectional: diabetes is associated with elevated risk and a less favorable periodontitis course, while untreated or unstable periodontitis is linked to poorer glycemic control. Successful periodontal therapy can improve glycemic control to a limited extent. Associations between periodontitis and other systemic conditions, including cardiovascular disease and pregnancy complications, are discussed in the literature; this does not automatically establish causation.

Treatment principles

The EFP S3 guideline for stage I to III describes a stepped treatment approach: (1) behavior change, control of supragingival biofilm, gingival inflammation, and risk factors; (2) supra- and subgingival instrumentation, with or without adjunctive measures; (3) various periodontal surgical procedures where indicated, including regenerative approaches in selected defect situations; (4) supportive periodontal therapy to maintain treatment outcomes long-term. For stage IV, marked by additional functional and anatomical consequences such as tooth drift or bite collapse, a complementary, interdisciplinary EFP S3 guideline has been available since 2022. The choice of intervention depends on stage and individual circumstances.

Guidelines

The German S3 clinical guideline on treating stage I to III periodontitis (AWMF 083-043, DG PARO / DGZMK, the German implementation of the EFP guideline) was published in December 2020. Its stated validity ended on 30 November 2025; it is currently listed as archived in the AWMF registry, with a revision in progress. A dedicated EFP S3 guideline for stage IV has existed since 2022 (Herrera et al.); a German implementation is registered under AWMF 083-056. The German S2k guideline on diabetes and periodontitis (AWMF 083-015, DG PARO / DDG / DGZMK, 2024) addresses the bidirectional relationship between the two conditions in detail.

Evidence summary

What current evidence supports

  • Periodontitis is internationally defined by clinical attachment loss detectable at two or more teeth, following the joint AAP/EFP classification
  • Staging and grading, incorporating smoking and diabetes as grade modifiers, provide a structured framework for individualized treatment planning
  • The relationship between periodontitis and diabetes is bidirectional, each condition capable of worsening the other
  • Global Burden of Disease 2021 data estimate age-standardized prevalence of severe periodontitis at approximately 12.5 percent worldwide

Why this matters

Because periodontitis often progresses silently, relying on symptoms to prompt a dental visit allows substantial, largely irreversible tissue loss to accumulate before anyone notices. Understanding periodontitis as a manageable, long-term condition rather than a one-time problem shifts the emphasis toward early detection and sustained supportive care, which is where outcomes are most within reach.

What remains uncertain

  • The precise mechanisms explaining individual variation in disease progression, beyond established risk factors like smoking and diabetes
  • How strongly and through what mechanisms periodontitis relates causally to systemic conditions such as cardiovascular disease, as opposed to sharing common risk factors
  • The long-term comparative effectiveness of different regenerative surgical techniques across varied defect types

Papapanou, Sanz, Buduneli, et al. (2018): Periodontitis: Consensus report of workgroup 2 of the 2017 World Workshop. Journal of Clinical Periodontology, 45(Suppl 20), S162-S170. Establishes the current internationally recognized case definition of periodontitis.

Tonetti, Greenwell, Kornman (2018): Staging and grading of periodontitis: Framework and proposal of a new classification and case definition. Journal of Clinical Periodontology, 45(Suppl 20), S149-S161. Consensus report establishing the staging and grading system. Corrigendum 2019 to specific appendix tables.

Sanz, Herrera, Kebschull, et al. (2020): Treatment of stage I-III periodontitis: The EFP S3 level clinical practice guideline. Journal of Clinical Periodontology, 47(Suppl 22), 4-60. Evidence-based treatment guideline, developed from 15 systematic reviews using GRADE methodology.

Herrera, Sanz, Kebschull, et al. (2022): Treatment of stage IV periodontitis: The EFP S3 level clinical practice guideline. Journal of Clinical Periodontology, 49(Suppl 24), 4-71. Complementary treatment guideline for stage IV with an interdisciplinary focus.

Global Burden of Disease 2021 (2025): Trends in the global, regional, and national burden of oral conditions from 1990 to 2021. Estimated global age-standardized prevalence of severe periodontitis at approximately 12.5 percent.

Sources

Guidelines:
📋 DG PARO / DGZMK: S3 Clinical Guideline on the Treatment of Stage I to III Periodontitis, German Implementation of the EFP Guideline, AWMF 083-043 (December 2020, validity ended 30 November 2025, archived, revision in progress).
📋 DG PARO / DDG / DGZMK: S2k Clinical Guideline on Diabetes and Periodontitis, AWMF 083-015, 2024.

International consensus and treatment guidelines:
📚 Papapanou PN, Sanz M, Buduneli N, et al. (2018): Periodontitis: Consensus report of workgroup 2 of the 2017 World Workshop. Journal of Clinical Periodontology, 45(Suppl 20), S162-S170.
📚 Tonetti MS, Greenwell H, Kornman KS (2018): Staging and grading of periodontitis. Journal of Clinical Periodontology, 45(Suppl 20), S149-S161.
📚 Corrigendum (2019) to Tonetti, Greenwell, Kornman (2018), staging/grading appendix tables.
📋 Sanz M, Herrera D, Kebschull M, et al. (2020): Treatment of stage I-III periodontitis, the EFP S3 level clinical practice guideline. Journal of Clinical Periodontology, 47(Suppl 22), 4-60.
📋 Herrera D, Sanz M, Kebschull M, et al. (2022): Treatment of stage IV periodontitis, the EFP S3 level clinical practice guideline. Journal of Clinical Periodontology, 49(Suppl 24), 4-71.

Epidemiology:
📚 GBD 2021 Oral Disorders Collaborators (2025): Trends in the global, regional, and national burden of oral conditions from 1990 to 2021.
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The KEERN Lexicon provides evidence-based educational information about oral health. It is intended to support, not replace, individual advice from a dentist, physician, or pharmacist. Diagnosis and treatment decisions should always be based on a personal clinical assessment.