Gingivitis vs Periodontitis: The Stages of Gum Disease Explained

Gum disease is often described as a single condition that gradually gets worse. That is only partly accurate, and the imprecision matters, because there is a specific point in the process where the situation changes character entirely.

Up to that point, the tissues can return fully to health. Beyond it, the objective changes from reversal to control. Understanding where that line sits — and how to tell which side of it you are on — is the most useful thing a patient can take from an article on this subject.

Gingivitis is inflammation confined to the gum tissue. The gums are red, swollen and bleed readily, but the bone and the fibres anchoring the tooth are intact. Remove the cause and the tissue returns to health.

Periodontitis is inflammation that has extended into the supporting structures. The periodontal ligament and the alveolar bone are progressively destroyed. That loss does not spontaneously regenerate, so treatment aims to halt progression and stabilise what remains rather than to restore what has gone.

The transition from one to the other is not inevitable, and it does not happen to everyone with gingivitis. Susceptibility varies considerably between individuals, influenced by genetics, smoking, diabetes control, stress and other factors.

Bacterial plaque accumulates at the gum margin. If it is not removed within a day or so it begins to mature and, where it remains undisturbed, mineralises into calculus — a hard deposit that cannot be brushed away and that provides a further surface for plaque to accumulate on.

The body responds with inflammation. Blood flow to the area increases, the tissue becomes engorged, and the capillaries become fragile.

• Gums that bleed when brushing or flossing — the earliest and most reliable sign. Our article on bleeding gums when brushing covers this in more detail.

• Redness at the gum margin instead of the normal pale pink.

• Slight swelling, with gum margins that look rounded rather than knife-edged.

• Persistent bad breath. Our article on whether halitosis is a gum problem discusses the connection.

• Tenderness, though frequently there is no pain at all.

The absence of pain is the reason gingivitis is so often ignored. Bleeding is dismissed as brushing too hard, when in almost all cases it indicates inflammation.

Thorough removal of plaque and calculus by a hygienist or therapist, followed by consistent daily home care — brushing twice daily and cleaning between the teeth every day. Where the cause is removed, the tissue typically returns to health within a matter of weeks. Our dental hygiene page explains what treatment involves, and our article on whether gum disease can be reversed without professional help addresses why home care alone is usually insufficient once calculus has formed.

Where inflammation persists, it extends beyond the soft tissue. The attachment between gum and tooth begins to break down, and a periodontal pocket forms — a space between tooth and gum that is deeper than the normal shallow sulcus.

Pockets are self-perpetuating. They are difficult to clean with a toothbrush, they harbour bacteria in an environment favourable to the more damaging species, and they deepen as the process continues. Early bone loss begins.

Frequently very little. Bleeding continues, bad breath may worsen, and there may be a change in how the gums feel. Pockets are not visible to the patient, which is why measurement at examination is essential.

Periodontal charting — probing around each tooth to measure pocket depth, bleeding on probing and recession — is how early periodontitis is identified. Radiographs show bone levels. Neither can be substituted by how the gums look in the mirror.

Pockets deepen further, and bone loss becomes more substantial. The proportion of root supported by bone reduces, and the tooth's stability begins to be affected.

• Gums that appear to be receding, making teeth look longer. Our receding gums page explains the causes.

• Increased sensitivity as root surfaces become exposed.

• Dark triangles appearing between the teeth as the gum papillae shrink.

• Slight mobility in some teeth.

• Discharge from the gum margin in some cases.

• Discomfort when chewing on particular teeth.

Non-surgical periodontal therapy — root surface debridement under local anaesthetic — carried out in stages across the mouth, followed by reassessment. Where pockets persist despite thorough treatment and good home care, surgical access may be considered. Our gum disease treatment page describes the pathway.

Modifiable risk factors are addressed at this point: smoking cessation, diabetes control, and correction of anything trapping plaque, such as overhanging restorations.

Extensive loss of the supporting bone. Teeth may have lost a substantial proportion of their attachment, and the remaining support is no longer adequate to resist normal functional forces.

• Teeth that are visibly loose or that shift position.

• Teeth drifting apart, creating new spaces where there were none before.

• A changing bite, with teeth meeting differently.

• Recurrent gum abscesses.

• Marked recession and root exposure.

• Difficulty chewing.

Stabilisation of what remains is the objective. This may involve surgical periodontal treatment, splinting of mobile teeth, and — where individual teeth have insufficient support to be maintained — extraction and planned replacement. Our article on clear aligners in patients with bone loss discusses orthodontic considerations where teeth have drifted.

Advanced cases require ongoing maintenance at short intervals indefinitely. Periodontitis is a condition that is controlled rather than eliminated.

Most people experience gingivitis at some point. Only a proportion progress to periodontitis, and severe forms affect a minority.

The factors that increase risk are reasonably well established:

• Smoking, which is among the strongest modifiable risk factors and also masks bleeding, delaying detection.

• Diabetes, particularly where blood glucose control is poor — the relationship runs in both directions.

• Genetic susceptibility, which influences the strength of the inflammatory response.

• Plaque retention factors such as crowding, ill-fitting restorations or partial dentures.

• Certain medications that cause gingival overgrowth.

• Hormonal changes, including pregnancy.

• Stress and reduced immune function.

The systemic connections are increasingly recognised. Our article on oral hygiene and chronic respiratory disease reviews one example of the current understanding.

At every routine dental check-up, with a full periodontal charting at appropriate intervals determined by risk. Patients with a history of periodontitis generally need shorter recall intervals — often every three to four months — because the condition can reactivate.

If you have never had pocket depths measured and recorded, it is worth asking. Bleeding gums that are treated as a cosmetic nuisance for years are how early disease becomes advanced disease.

If your gums bleed, if you have never had a periodontal assessment, or if it has been some time since your last one, that is the point at which to act rather than wait.

You can arrange an assessment at our Wimpole Street practice, where pocket depths, bone levels and risk factors can be reviewed together and a maintenance interval agreed.

This article is provided for general information only and does not constitute personalised dental advice. Diagnosis of gingivitis or periodontitis, and decisions about treatment, require an individual clinical examination by a registered dental professional. All treatment carries potential risks and benefits that should be discussed with your clinician before proceeding.

Next review due: 10 September 2027