Gingivitis

Gingivitis is inflammation of the gums caused by plaque sitting against them. It is extremely common, it is usually painless, and — this is the part that matters — it is completely reversible. Clean the plaque off properly and the gums heal, with no permanent damage. Leave it, and in a susceptible person it can become periodontitis, which is not reversible.

Table of Contents

1. What Gingivitis Is
2. Reversible — and Why That Word Matters
3. Causes and Risk Factors
4. Symptoms and Warning Signs
5. How Gingivitis Is Diagnosed
6. Treatment
7. Prevention and Daily Care
8. What the Evidence Does Not Support
9. Complications and Systemic Links
10. Necrotizing Gingivitis
11. When to See a Dentist
12. Key Research Papers
13. Connections
14. Featured Videos

What Gingivitis Is

Gingivitis is inflammation confined to the gingiva — the collar of gum tissue around each tooth. It is the body’s immune response to the bacterial biofilm (dental plaque) that accumulates at and just below the gumline. The tissue becomes red, swollen, and prone to bleeding. The key anatomical fact is what is not happening: the periodontal ligament fibres holding the tooth to the bone are intact, and the alveolar bone is intact. Nothing has been destroyed. Only the soft tissue is angry.

Plaque is not simply food debris. It is an organised biofilm — a structured microbial community embedded in a self-produced matrix that makes its residents dramatically more resistant to antimicrobials and to the immune system than the same bacteria would be floating free. It begins re-forming on a clean tooth surface within hours. This is why oral hygiene is a daily mechanical chore and not something you can accomplish once with a strong enough mouthwash.

Gingivitis is the most common form of periodontal disease and one of the most prevalent inflammatory conditions in humans. Most adults have it somewhere in the mouth at any given moment. Because it rarely hurts, most of them do not know.

Reversible — and Why That Word Matters

The distinction between gingivitis and periodontitis is the single most useful thing to understand about gum disease, and it is routinely blurred — by toothpaste advertising, and sometimes by patients being told only that they have “gum problems.”

• Gingivitis — inflammation of the gum tissue only. No clinical attachment loss. No bone loss. Fully reversible. Remove the plaque and the tissue returns to health, typically within one to two weeks.
• Periodontitis — the inflammation has extended into the supporting structures. The attachment of gum to tooth breaks down, a pocket forms, and the alveolar bone resorbs. Not reversible. Treatment can arrest it, often permanently, but the lost bone and lost attachment do not come back on their own.

The classic demonstration is Löe, Theilade and Jensen’s Experimental Gingivitis in Man (1965), one of the most important papers in dentistry. Healthy volunteers were asked to stop all oral hygiene. Plaque accumulated, and every single subject developed clinical gingivitis — most within about ten days to three weeks. Then they were told to resume brushing. The gingivitis resolved, in around a week, in all of them. Cause established, reversibility established, in one elegant experiment.

That reversibility has an expiry date. Gingivitis does not inevitably become periodontitis — many people carry it for years without progressing — but periodontitis is essentially always preceded by gingivitis. Preventing and resolving gingivitis is therefore the only proven route to primary prevention of periodontitis. Bleeding gums are the last warning you get while the damage is still free to undo.

Causes and Risk Factors

The Primary Cause

Dental plaque. In the overwhelming majority of cases, gingivitis is plaque-induced, and the amount and duration of plaque against the gum margin drives the amount of inflammation. Everything below either increases plaque accumulation or amplifies the body’s inflammatory response to it.

Local Factors That Trap Plaque

• Inadequate or ineffective brushing — particularly missing the gumline itself, which is exactly where it counts.
• No interdental cleaning — a toothbrush cannot reach between the teeth, and that is where gum disease most often begins.
• Crowded, crooked, or rotated teeth, which create sheltered surfaces.
• Overhanging fillings, poorly contoured crowns, and ill-fitting partial dentures, which create plaque traps at the gumline.
• Orthodontic appliances — fixed braces make plaque control genuinely difficult.
• Calculus (tartar) — mineralised plaque. It is not itself the cause, but its rough surface is an ideal scaffold for fresh plaque, and it cannot be brushed off. Only a dental professional can remove it.
• Mouth breathing and dry mouth (xerostomia), which remove saliva’s natural cleansing and buffering.

Systemic and Host Factors

• Smoking and vaping — a major risk factor, with a treacherous quirk: nicotine constricts gingival blood vessels, so smokers bleed less. A smoker can have substantial disease with deceptively healthy-looking gums. Absence of bleeding in a smoker is not reassurance.
• Diabetes, especially when poorly controlled — hyperglycaemia amplifies the inflammatory response and impairs healing.
• Hormonal change — puberty, the menstrual cycle, pregnancy, and hormonal contraceptives all exaggerate the gingival response to the same amount of plaque. “Pregnancy gingivitis” is common and is a modified response to plaque, not a separate disease; the plaque still has to go.
• Medications causing gingival overgrowth — phenytoin (anticonvulsant), ciclosporin (immunosuppressant), and calcium-channel blockers such as nifedipine and amlodipine. The enlarged tissue is far harder to keep clean, which compounds the problem.
• Medications causing dry mouth — many antidepressants, antihistamines, diuretics, and antihypertensives.
• Stress, malnutrition, and immunosuppression (including HIV infection).
• Severe vitamin C deficiency (scurvy) — rare in developed countries but still seen in people with very restricted diets, alcohol dependence, or eating disorders. It causes strikingly swollen, spongy, bleeding gums, because vitamin C is required for collagen synthesis. It is worth remembering precisely because it is treatable and often missed.
• Leukaemia — leukaemic infiltration of the gingiva can present as swollen, boggy, spontaneously bleeding gums. This is uncommon, but it is one of the reasons gums that bleed heavily and without provocation deserve proper assessment rather than a new toothpaste.

Gingivitis That Is Not Caused by Plaque

A minority of gingival disease is non-plaque-induced: primary herpetic gingivostomatitis (a viral infection, usually in children, causing painful ulcers and fever), oral candidiasis, oral lichen planus, mucous membrane pemphigoid, and allergic or contact reactions (including to some toothpaste flavourings, notably cinnamon). These do not respond to better brushing and need a specific diagnosis.

Symptoms and Warning Signs

The defining sign is bleeding. Healthy gums do not bleed when brushed. If yours do, that is inflammation, not a brush that is too hard, and not something to brush around more gently.

• Bleeding when brushing or flossing — the cardinal sign, and often the only one.
• Red or purplish gums instead of firm, pale pink.
• Swollen, puffy, shiny gums that have lost their stippled, orange-peel texture.
• Tenderness to touch (though frank pain is unusual — pain suggests something else, such as an abscess or necrotizing disease).
• Bad breath or a persistent bad taste (see Halitosis).
• Gums that appear to be receding — though true recession is more characteristic of periodontitis or of over-vigorous brushing.

What you should not have with simple gingivitis: loose teeth, teeth that have shifted position, pus, deep pockets, or gaps opening between the teeth. Any of those means the disease has moved past gingivitis, and you should read the periodontitis page.

How Gingivitis Is Diagnosed

Diagnosis is clinical and takes minutes. A dentist or hygienist runs a calibrated periodontal probe gently around each tooth — conventionally six sites per tooth — and records two things:

1. Probing depth — how deep the crevice between gum and tooth is. Up to about 3 mm is normal. Gingivitis can produce “pseudo-pockets” of 4 mm or more purely because the swollen gum sits higher up the tooth, but the attachment underneath is still at its original level.
2. Bleeding on probing (BOP) — whether the site bleeds in response to gentle probing. This is the objective measure of inflammation, and it is the one that defines the diagnosis.

Under the 2017 World Workshop case definition, on an intact periodontium:

• Periodontal health — bleeding at less than 10% of sites.
• Localised gingivitis — bleeding at 10–30% of sites.
• Generalised gingivitis — bleeding at more than 30% of sites.

The crucial measurement that separates gingivitis from periodontitis is clinical attachment level (CAL) — the distance from a fixed landmark on the tooth (the cementoenamel junction) to the base of the pocket. In gingivitis, CAL is unchanged. In periodontitis, it has been lost. Radiographs (usually bitewings) confirm the other half of the picture: in gingivitis the bone crest is at a normal height; in periodontitis it is not.

A patient who has previously had periodontitis, been treated, and become stable can still develop gingivitis on their reduced periodontium. In that situation bleeding is treated as a warning of possible recurrence and is taken more seriously.

Treatment

Treatment is unglamorous and highly effective: remove the plaque and the calculus, then keep the plaque off.

1. Professional Cleaning

The dentist or hygienist removes plaque and calculus above and just below the gumline with hand instruments and ultrasonic scalers. Calculus cannot be removed by brushing; as long as it is there, it will keep seeding fresh plaque. If overhanging restorations or badly contoured crowns are trapping plaque, correcting them is part of the treatment, not an optional extra.

2. Oral Hygiene Instruction — the part that actually decides the outcome

A professional cleaning that is not followed by better daily technique buys you a few weeks. This is a home-care disease. Expect to be shown, specifically, where you are missing.

3. Risk-Factor Control

Smoking cessation. Glycaemic control if diabetic. Review of medications causing dry mouth or gingival overgrowth (with the prescribing doctor — do not stop anything unilaterally).

4. Antiseptic Adjuncts — short-term, and adjuncts only

• Chlorhexidine mouthrinse is genuinely effective. A Cochrane review found that chlorhexidine rinse added to usual mechanical care produces a clear reduction in gingivitis. But it stains teeth and the tongue brown with prolonged use, can alter taste, and is intended for short courses (typically a few weeks) — around surgery, during an acute episode, or when brushing is temporarily impossible. It is not a long-term substitute for a toothbrush, and it should not be used indefinitely.
• Essential-oil mouthrinses (the thymol/eucalyptol/menthol/methyl-salicylate class) have meta-analytic support as an adjunct for reducing plaque and gingivitis, with less staining than chlorhexidine.
• Cetylpyridinium chloride (CPC) rinses have modest adjunctive evidence.

Note the consistent word: adjunct. No rinse penetrates a mature biofilm the way a brush bristle disrupts it. Rinsing instead of brushing does not work.

5. Antibiotics

Systemic antibiotics have no role in ordinary plaque-induced gingivitis. It is not an infection to be sterilised; it is an inflammatory response to a biofilm that has to be physically removed. (Necrotizing gingivitis is the exception — see below.)

Timeline

With plaque properly controlled, expect visible improvement within days and resolution of bleeding in one to two weeks. If your gums are still bleeding after two to three weeks of genuinely good hygiene, go back — either the technique is missing something, there is subgingival calculus still in place, or the diagnosis is not simple gingivitis.

Prevention and Daily Care

Brushing

• Twice a day, two minutes, with a fluoride toothpaste.
• Use a soft brush. Hard bristles do not clean better; they abrade enamel and cause gum recession.
• Angle the bristles about 45° toward the gumline and use short strokes or small circles. The gum margin is the target. Scrubbing the flat middle of the tooth achieves very little.
• Powered brushes help, modestly but genuinely. The Cochrane review found powered brushes reduce plaque and gingivitis more than manual brushing — roughly a 6% greater reduction in gingivitis in the short term and around 11% at three months or more, with oscillating-rotating designs having the best evidence. That is a real benefit, not a transformative one. A well-used manual brush beats a badly-used electric one.

Cleaning Between the Teeth

This is the step most people skip, and it is where gum disease starts.

• Interdental brushes are the first choice wherever the space allows one to fit. They clean the interdental surface far more effectively than floss, and European periodontal guidance now recommends them ahead of floss for that reason.
• Floss is for tight contacts where an interdental brush will not pass. Be honest about the evidence: the Cochrane review of flossing found only weak and unreliable evidence that flossing plus brushing reduces gingivitis compared with brushing alone, and insufficient evidence on plaque. This does not mean flossing is useless — the trials were small, short, and poorly conducted, and “we have not proven it” is not the same as “it does not work.” It does mean that if you have gaps big enough for an interdental brush, use the interdental brush.

Other

• Do not smoke or vape.
• Keep blood glucose controlled if you are diabetic.
• Reduce the frequency of sugary food and drink (this matters more for tooth decay than for gingivitis, but it is the same brush).
• Stay hydrated; treat dry mouth.
• See a dentist regularly. Worth knowing, though: a Cochrane review of routine six-monthly scale-and-polish in generally healthy adults found little or no difference in gingivitis over two to three years. That finding applies to routine polishing in low-risk people — it is not a reason to skip periodontal treatment if you actually have disease, and it is not an argument against check-ups, which are also screening for decay and oral cancer.

What the Evidence Does Not Support

Two popular remedies come up constantly, and both deserve a straight answer.

Oil Pulling

Swishing coconut or sesame oil for 10–20 minutes is an ancient Ayurvedic practice now marketed heavily for gum health. The published trials are small, short, and at high risk of bias, and reviews of the literature conclude the evidence is insufficient to recommend it as a replacement for standard oral hygiene. It is not obviously harmful in itself, but it is not a substitute for brushing, and two cautions apply: there are case reports of lipoid pneumonia from accidental aspiration of the oil, and time spent oil pulling is time not spent doing something that works. If you enjoy it, do it after you brush and clean between your teeth — not instead.

Charcoal Toothpaste

Activated-charcoal dentifrices are cosmetically popular and poorly supported. A review in the Journal of the American Dental Association found insufficient clinical or laboratory data to substantiate the safety and efficacy claims, and raised concrete concerns: many charcoal pastes are abrasive and can wear enamel and dentine (a loss that, like bone loss, does not come back); most contain no fluoride, removing the single best-evidenced ingredient in toothpaste; and charcoal particles can lodge around the gum margin and in the edges of restorations. Charcoal toothpaste is a downgrade, not an upgrade.

The General Rule

Gingivitis is caused by a biofilm stuck to a tooth. It is resolved by physically removing that biofilm. Anything that does not do that — rinses used alone, oils, powders, supplements — is at best an adjunct and at worst a distraction.

Complications and Systemic Links

The complication that matters is progression to periodontitis, and with it irreversible attachment loss, bone loss, and eventual tooth loss. Untreated gingivitis is not dangerous in itself. It is dangerous as a doorway.

Other consequences:

• Chronic bad breath — inflamed, bleeding gum tissue is a rich source of the volatile sulfur compounds behind halitosis.
• Gingival abscess — a localised, painful collection of pus, usually where something has been forced into the gum.
• Pregnancy — periodontal disease is associated with adverse pregnancy outcomes including preterm birth and low birth weight. The association is real and biologically plausible; treatment trials, however, have not consistently shown that treating gum disease during pregnancy improves those outcomes. Treat pregnancy gingivitis because it is uncomfortable, progressive, and easy to fix — dental treatment is safe in pregnancy — not because you have been promised it will prevent preterm birth.

On the broader oral–systemic story: the epidemiological associations between periodontal disease and cardiovascular disease, diabetes, and rheumatoid arthritis are attached mainly to periodontitis, not to gingivitis, and are discussed honestly on the periodontitis page. Be sceptical of anyone selling you a mouthwash on the strength of your heart.

Necrotizing Gingivitis

Necrotizing gingivitis (NG; historically ANUG, or “trench mouth” — it was rife in the trenches of the First World War) is a distinct, acute, and genuinely painful condition that is not just severe ordinary gingivitis. It is uncommon, and it is a dental urgency.

Recognise it by:

• Severe pain — unlike ordinary gingivitis, which does not hurt much.
• “Punched-out,” ulcerated, cratered interdental papillae — the little triangles of gum between the teeth look eroded away.
• A grey pseudomembrane covering the ulcers.
• Spontaneous bleeding — without provocation.
• A distinctive, strongly foul odour.
• Sometimes fever, malaise, and swollen lymph nodes.

It clusters in people who are stressed, smoking, malnourished, sleep-deprived, or immunocompromised — classically students in exam season, and, importantly, people with untreated HIV infection, in whom it can be an early sign. Treatment is prompt professional debridement plus, in this case, systemic antibiotics (typically metronidazole), pain relief, and management of the underlying risk factors. Seek same-day dental care.

When to See a Dentist

Book an appointment if:

• Your gums bleed when you brush or floss — and keep bleeding after two weeks of careful, thorough daily cleaning.
• Your gums are persistently red, swollen, or tender.
• You have bad breath or a bad taste that does not resolve with good hygiene.
• You are pregnant, or planning to be, and your gums bleed.
• You smoke — and especially if you smoke and your gums do not bleed but look otherwise unhealthy.
• You have diabetes. Periodontal screening should be part of routine diabetes care.
• You have not had a dental examination in over a year.

Seek urgent (same-day) dental care if:

• You have severe gum pain, ulcerated or “punched-out” gums, and foul breath — possible necrotizing gingivitis.
• You have facial swelling, fever, or pus — possible abscess. Facial swelling that is spreading, closing the eye, or affecting swallowing or breathing is a medical emergency, not a dental one: go to an emergency department.
• A tooth has become loose or has moved.

See a doctor as well if:

• Your gums bleed spontaneously and heavily, without brushing.
• Gum bleeding comes with easy bruising, nosebleeds, unusual fatigue, or fever — this combination warrants a blood count to exclude a haematological cause.
• You have a very restricted diet and grossly swollen, spongy gums — ask about vitamin C.

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Key Research Papers

Peer-reviewed literature underpinning the diagnosis, treatment, and prevention of gingivitis. Each citation links to the full text via DOI.

1. Löe H, Theilade E, Jensen SB. Experimental Gingivitis in Man. Journal of Periodontology. 1965;36(3):177–187. — The landmark experiment establishing plaque as the cause of gingivitis, and its reversibility.
2. Trombelli L, Farina R, Silva CO, Tatakis DN. Plaque-induced gingivitis: Case definition and diagnostic considerations. Journal of Clinical Periodontology. 2018;45(Suppl 20):S44–S67.
3. Murakami S, Mealey BL, Mariotti A, Chapple ILC. Dental plaque-induced gingival conditions. Journal of Clinical Periodontology. 2018;45(Suppl 20):S17–S27.
4. Chapple ILC, Mealey BL, Van Dyke TE, et al. Periodontal health and gingival diseases and conditions on an intact and a reduced periodontium: Consensus report of workgroup 1 of the 2017 World Workshop. Journal of Clinical Periodontology. 2018;45(Suppl 20):S68–S77. — Source of the 10% bleeding-on-probing threshold.
5. Chapple ILC, Van der Weijden F, Doerfer C, et al. Primary prevention of periodontitis: managing gingivitis. Journal of Clinical Periodontology. 2015;42(Suppl 16):S71–S76.
6. Yaacob M, Worthington HV, Deacon SA, et al. Powered versus manual toothbrushing for oral health. Cochrane Database of Systematic Reviews. 2014;(6):CD002281.
7. Sambunjak D, Nickerson JW, Poklepovic T, et al. Flossing for the management of periodontal diseases and dental caries in adults. Cochrane Database of Systematic Reviews. 2011;(12):CD008829.
8. Poklepovic T, Worthington HV, Johnson TM, et al. Interdental brushing for the prevention and control of periodontal diseases and dental caries in adults. Cochrane Database of Systematic Reviews. 2013;(12):CD009857.
9. James P, Worthington HV, Parnell C, et al. Chlorhexidine mouthrinse as an adjunctive treatment for gingival health. Cochrane Database of Systematic Reviews. 2017;3(3):CD008676.
10. Araujo MWB, Charles CA, Weinstein RB, et al. Meta-analysis of the effect of an essential oil-containing mouthrinse on gingivitis and plaque. Journal of the American Dental Association. 2015;146(8):610–622.
11. Worthington HV, Clarkson JE, Bryan G, Beirne PV. Routine scale and polish for periodontal health in adults. Cochrane Database of Systematic Reviews. 2018;12:CD004625.
12. Marsh PD. Dental plaque as a biofilm and a microbial community — implications for health and disease. BMC Oral Health. 2006;6(Suppl 1):S14.
13. Herrera D, Retamal-Valdes B, Alonso B, Feres M. Acute periodontal lesions (periodontal abscesses and necrotizing periodontal diseases) and endo-periodontal lesions. Journal of Clinical Periodontology. 2018;45(Suppl 20):S78–S94. — Necrotizing gingivitis.
14. Figuero E, Han YW, Furuichi Y. Periodontal diseases and adverse pregnancy outcomes: Mechanisms. Periodontology 2000. 2020;83(1):175–188.
15. Shanbhag VKL. Oil pulling for maintaining oral hygiene — A review. Journal of Traditional and Complementary Medicine. 2017;7(1):106–109.
16. Brooks JK, Bashirelahi N, Reynolds MA. Charcoal and charcoal-based dentifrices: A literature review. Journal of the American Dental Association. 2017;148(9):661–670.

Live PubMed Searches

1. PubMed: gingivitis randomised controlled trials
2. PubMed: experimental gingivitis
3. PubMed: bleeding on probing
4. PubMed: chlorhexidine and gingivitis
5. PubMed: pregnancy gingivitis
6. PubMed: necrotizing ulcerative gingivitis
7. PubMed: drug-induced gingival overgrowth
8. PubMed: interdental brush versus floss

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Connections

• How Cavities Form — interactive animation
• Dentistry & Oral Health
• All Conditions
• Periodontitis (Gum Disease)
• Halitosis (Chronic Bad Breath)
• Tooth Decay (Dental Caries)
• Oral Microbiome
• Myrrh
• Myrrh for Oral Health
• Aloe Vera — Oral and Dental
• Vitamin C
• Type 2 Diabetes

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