What Is Periodontal Disease?
A Complete Clinical Guide

Healthy gum tissue is coral pink, firm, and does not bleed when gently probed. Pocket depths measure 1-3mm around all teeth. There is no bone loss, no recession, and no clinical signs of infection. Maintaining healthy gingiva requires twice-daily brushing with a soft-bristle brush, daily flossing to disrupt interproximal plaque, and regular 6-month professional cleanings. At this stage, preventive care is straightforward and inexpensive — the best outcome is simply to stay here.

Gingivitis is the earliest stage of gum disease — and the only stage that is fully reversible. Bacterial plaque accumulates at the gum margin, triggering an inflammatory response in the gum tissue. The gums become red, puffy, and bleed easily on brushing or probing. Critically, there is no bone loss at this stage — all changes are confined to the soft tissue. With thorough professional cleaning and improved home care, gingivitis can resolve completely within 2-4 weeks, restoring the gums to full health. The window for easy reversal is at this stage — once bone loss begins, the disease has progressed to periodontitis.

If gingivitis is not addressed, the bacterial infection extends deeper into the sulcus, and the body's immune response begins to destroy the supporting bone and connective tissue. Pocket depths increase to 4-5mm. On a radiograph, early horizontal bone loss becomes visible at the crests of the alveolar bone between teeth. The patient may not feel pain — periodontal disease is notoriously painless until advanced stages. This is why regular periodontal probing and digital X-rays are essential: they detect disease long before it is symptomatic. Scaling and root planing at this stage is very effective at halting disease progression.

Moderate periodontitis involves progressive deepening of pockets to 5-7mm with significant clinical attachment loss — the gum tissue has detached from the root surface, allowing bacteria to colonise deeper into the supporting apparatus. Radiographs show moderate bone loss around multiple teeth, sometimes with angular defect patterns that reflect localised severe disease at specific sites. Furcation involvement — bone loss between the roots of molar teeth — may begin. Patients may notice increased sensitivity, occasional gum soreness, and worsening bad breath. Treatment requires scaling and root planing under local anesthesia, and some cases will require surgical management.

Advanced periodontitis represents severe destruction of the periodontal supporting apparatus. Pocket depths exceed 7mm at multiple sites. Teeth develop mobility as the bone support diminishes — a tooth that previously required firm force to extract may now be loose in its socket. Radiographic bone loss is extensive, often exceeding 50% of root length. Patients may notice teeth drifting, changes in bite, difficulty chewing, and visible lengthening of the teeth from gum recession. Without intervention, tooth loss is the outcome. Regenerative surgical procedures and intensive maintenance can sometimes salvage teeth at this stage — but prevention at earlier stages is always preferable.