Causes of Gingivitis, Periodontitis & Gum Disease

DHCP with patient

Poor oral hygiene is the major cause of periodontal disease and gingivitis1,2

Take a closer look at the causes and mechanisms behind the condition, with a particular focus on why poor oral hygiene is the major cause of periodontal disease1,2

Periodontal disease is caused by plaque1–4

  • Periodontal disease is caused by bacteria at the gum margin forming plaque on the dental pellicle1,3
  • Endotoxins and bacterial debris released by these plaque bacteria cause inflammation in the surrounding gum known as gingivitis1,2,4
  • If plaque is not removed, over time this inflammatory response can become chronic periodontitis, leading to progressive tissue destruction1,2

The new classification was developed at the 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases. For the first time this included:7

  • A formal definition of periodontal health
  • The use of staging and grading to further classify periodontitis
  • The inclusion of peri-implant diseases

Click here to download the quick guide to the new classification

Progression of gingivitis and periodontal disease

Gingivitis is a reversible condition that develops from healthy gums when plaque around the gum line induces inflammation of the gingivae. If left untreated, chronic gingival inflammation can progress into chronic periodontitis, causing irreversible destruction of the periodontal tissues. While not all gingivitis becomes progressive, almost half of adults are susceptible.2

Healthy gums cross-section

Healthy gums and preventing gingivitis

The World Workshop on the Classification2017 of Periodontal and Peri-implant Diseases defined periodontal health as:5

  • Absence of clinically detectable inflammation
  • Intact periodontium – no clinical attachment loss or bone loss

Characteristics include:

  • Pale pink and firm gingivae
  • Stippled
  • Firmly attached to teeth
  • Knife-edge margin
  • Not normally prone to bleeding on brushing or probing

This may now also include patients who have a history of successfully treated gingivitis or periodontitis who have been or are able to maintain their dentition without signs of clinical gingival inflammation.5

Gums with gingivitis cross-section

Diagnosing gingivitis

Reversible plaque-induced inflammation of the gingivae.2Characteristics include:

  • Change in colour of the gingivae
  • Marginal gingival swelling and blunting of the gingival papillae
  • Bleeding on probing and brushing
  • Probing depth of gingival crevice does not exceed 3mm
  • Gingival attachment remains unchanged

Symptoms a patient may mention include:5

  • Bleeding gums (metallic/altered taste)
  • Pain (soreness)
  • Halitosis
  • Difficulty eating
  • Appearance (red/swollen gums)
  • Reduced oral health related quality of life

In the new classification following the 2018 World Workshop, gingivitis can be simply defined and graded using bleeding on probing percentage scores. Ginigivitis is diagnosed when a patient has BOP scores >10% and pocket depths <3mm.5

Gums with periodontitis cross-section


Irreversible destruction of the periodontal tissues caused by chronic inflammation.2 Characteristics include:

  • Gingivae appear inflamed
  • Bleeding on probing and brushing
  • Destruction of junctional epithelium and loss of gingival attachment (true pocketing and recession)
  • Alveolar bone loss
  • Tooth mobility and drifting

In the new periodontal disease classification guidelines, the previous terms of ‘chronic’ and ‘aggressive’ in relation to periodontitis are now grouped under the term periodontitis.6 The condition is then further characterized based on staging and grading.6

A stable periodontitis patient remains at higher risk for recurrent disease compared to a gingivitis or healthy patient.5

Find out more

Risk factors for periodontal disease can be divided into two categories2

Bacteria on tooth

Modifiable risk factors

Local risk factors5Local risk factors, which are also known as predisposing factors for plaque accumulation vary by patient and include:

  • Dental plaque retention factors e.g. removable partial dentures and anatomic factors such as malpositioned teeth
  • Oral dryness – associated with reduced dental biofilm removal

Systemic risk factors5These are characteristics present in an individual which negatively influence the immune-inflammatory response and include:

  • Smoking
  • Metabolic factors e.g. diabetes
  • Nutritional factors e.g. vitamin C deficiency
  • Pharmacological agents which may reduce salivary flow or may induce gingival enlargement
  • Elevations in sex hormones e.g. puberty or pregnancy
  • Hematological conditions e.g. Leukaemia

Targeting modifiable risk factors, such as poor oral hygiene, can improve gum health management and treatment outcomes

Dental patient at practice reception

Patient barriers to preventing gingivitis and maintaining gum health

Hard-to-reach areas

  • Any irregularity that makes tooth cleaning difficult can encourage the accumulation of plaque,8,9 including:
    • Malpositioned teeth8
    • Overhanging edges on fillings8
    • Poorly contoured fillings8
    • Some types of dentures8
  • Calculus (tartar) formation may cause plaque retention8

Patients ignore symptoms and professional advice

The early symptoms of gum disease may be ignored for a number of possible reasons:

  • Lack of awareness of gum health importance (believing bleeding gums to be ‘normal’)
  • A belief that teeth are more important than gums
  • More focus on current cosmetic issues rather than on possible future issues caused by periodontal disease
  • Expect dental practitioner to fix gum issues instead of proactively managing own gum health

Discover more about treating dental patients by browsing our educational resources.

Help your patients on their journey to preventing gingivitis and gum disease while promoting healthy gums

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Impact on patient quality of life

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Explore an overview of diagnosing periodontal disease.

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Gum health

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The Corsodyl range

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Patient care resources

Download resources for your patients.

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