Gum disease is a bacterial infection of the tissues holding your teeth in place. It begins as gingivitis, where plaque at the gum line inflames the gum and makes it bleed, and it is completely reversible at that point. If plaque is left to harden into tartar below the gum line, the infection progresses to periodontitis, where the body’s own inflammatory response destroys the ligament and bone anchoring the tooth. That bone loss is permanent. Roughly 42 percent of US adults over 30 have some periodontitis, rising to over 60 percent after 65, and the early stages are usually painless.
How gum disease develops
Plaque, the soft film of bacteria that forms on teeth every day, collects in the shallow groove where the tooth meets the gum. Within a day or two the bacteria there shift toward species that thrive without oxygen and release toxins. The gum responds with inflammation: swelling, redness, and fragile blood vessels that bleed at a touch. This is gingivitis.
If the plaque is removed daily, the inflammation resolves within one to two weeks and nothing is lost. If it is not, the plaque mineralises into tartar within 24 to 72 hours. Tartar is rough and porous, holds more plaque, and extends below the gum line where no toothbrush reaches. Our guide to plaque vs tartar covers that transition in detail.
At that point the inflamed gum begins to detach from the tooth, forming a pocket. Pockets are anaerobic, impossible to clean at home, and they deepen. The destructive step is the body’s own response: the prolonged inflammation breaks down the periodontal ligament and resorbs the bone socket. The tooth loosens. This is periodontitis, and the bone it destroys does not regrow.
The stages
Stage 1: Gingivitis. Gums are red, puffy, and bleed when brushing or flossing. Possible bad breath. No bone loss, no pockets deeper than 3 mm. Fully reversible.
Stage 2: Early periodontitis. Pockets of 4 to 5 mm. Bleeding on probing, some bone loss visible on X-rays, gums may begin to recede. Usually still painless. Can be halted; bone already lost stays lost.
Stage 3: Moderate periodontitis. Pockets of 6 to 7 mm. More noticeable recession, teeth may feel slightly loose, possible bad taste and persistent bad breath, gums may release pus when pressed.
Stage 4: Advanced periodontitis. Pockets over 7 mm, significant bone loss, teeth visibly loose, shifting, or drifting apart, pain on chewing, abscesses. Teeth may be lost or need extraction.
Dentists measure this with a small probe at a check-up, calling out numbers for each tooth. Those numbers are pocket depths in millimetres. Three or less is healthy.
Symptoms worth acting on
- Gums that bleed when brushing or flossing, the earliest and most reliable sign
- Red, swollen, or tender gums rather than firm and pale pink
- Persistent bad breath or a bad taste that cleaning does not fix
- Gums pulling back, teeth looking longer, or new sensitivity at the gum line
- A gap appearing between gum and tooth
- Pus at the gum margin
- Teeth that feel loose, shift position, or no longer bite together the way they did
- Dentures that have stopped fitting
Pain is conspicuously absent from the early stages. That is the whole problem: by the time gum disease hurts, it has usually been progressing for years.
Risk factors you can and cannot change
Changeable: inadequate plaque removal, smoking (the single biggest modifiable risk, and it also masks bleeding by constricting blood vessels), uncontrolled diabetes, stress, and a diet high in refined carbohydrate.
Not changeable: genetics, which strongly influences who progresses; age; hormonal changes in pregnancy and menopause; some medications that cause dry mouth or gum overgrowth; and conditions that suppress immunity.
The relationship with diabetes runs both ways. Periodontitis makes blood sugar harder to control, and poorly controlled diabetes accelerates gum disease. Treating one helps the other.
Treatment and what it costs
Gingivitis. A professional cleaning to remove tartar, plus corrected home care: twice-daily brushing angled into the gum line and daily cleaning between the teeth. A routine cleaning costs $75 to $200 in the US and is usually covered in full by dental insurance. Gums should be healthy within two to three weeks.
Early to moderate periodontitis. Scaling and root planing, a deep cleaning under local anaesthetic that removes tartar from the root surfaces inside the pockets. Usually done over two to four visits, one quadrant at a time. $150 to $350 per quadrant; insurance typically covers it as a basic service. Afterward, maintenance cleanings every three to four months rather than six.
Advanced periodontitis. Referral to a periodontist. Options include flap surgery to access deep deposits, bone or tissue grafting to regenerate some support, and extraction of teeth too loose to save. Costs run from $600 to $4,000 per quadrant depending on the procedure.
Adjuncts sometimes used alongside: locally delivered antibiotics placed into a pocket, a short course of systemic antibiotics in aggressive cases, and prescription chlorhexidine rinse for a few weeks. For over-the-counter options, see our guide to mouthwash for gingivitis.
Treatment arrests the disease. It does not rebuild what has gone, which is the reason the bleeding-gums stage is the one worth acting on.
Preventing it
Nothing exotic: brush twice daily for two minutes with the bristles angled into the gum line, clean between the teeth every day with floss, interdental brushes, or a water flosser, and have a professional cleaning every six months, or every three to four if you have had periodontitis. Stop smoking. Keep diabetes well controlled. Our guides to bleeding gums and how often to floss cover the daily routine.
When to see a dentist
See a dentist if your gums bleed when you brush and have not stopped after two weeks of careful daily cleaning; if gums are swollen, tender, or have pulled away from the teeth; if there is pus, a persistent bad taste, or bad breath that cleaning does not fix; if any tooth feels loose or has moved; or if you have not had a professional cleaning in the past year. Go sooner if you have diabetes and any gum bleeding, if you are pregnant, or if you smoke, since smoking suppresses bleeding and can hide advanced disease. Facial swelling with fever is an emergency: contact a dentist the same day or go to urgent care.
Frequently asked questions
Can gum disease be reversed?
Gingivitis can be reversed completely with good cleaning and a professional scale. Periodontitis cannot: treatment stops it progressing and the gums become healthy again, but bone already destroyed does not grow back.
Is gum disease painful?
Usually not until the late stages, which is why it is so often missed. Bleeding gums, bad breath, and recession appear long before pain. Treat bleeding as the warning sign rather than waiting for discomfort.
How long does it take gingivitis to become periodontitis?
There is no fixed timeline. Gingivitis can persist for years without progressing, and not everyone progresses at all. Smokers, people with uncontrolled diabetes, and those with a genetic predisposition progress faster. Since nobody can tell in advance, the safe assumption is that it will.
Does gum disease cause tooth loss?
Advanced periodontitis is the leading cause of tooth loss in adults over 35. Teeth loosen as the supporting bone is destroyed, and eventually cannot be saved. Caught at the gingivitis or early periodontitis stage, it does not reach that point.
Is gum disease linked to other health problems?
Periodontitis is associated with cardiovascular disease, poorly controlled diabetes, rheumatoid arthritis, and adverse pregnancy outcomes. The association is consistent; whether gum disease causes these conditions or shares common inflammatory risk factors is still being studied. The two-way relationship with diabetes is the best established.
