By Prof. Beena Rani Goel

Periodontal disease is caused by overgrowth of bacteria on the dentogingival surfaces. The treatment is aimed at checking this bacterial overgrowth by careful debridement of the tooth surfaces. Periodontal surgery is performed to provide better access for debridement. In recent years, there is a shift in the treatment paradigm. Systemic antibiotics are administered to those 15 to 20% of patients who do not respond to conventional debridement procedure.

The non-specific plaque hypothesis is the prevailing basis of treatment for periodontal disease. According to this, the overgrowth of any or all-bacterial species on the tooth surfaces causes an inflammatory response in the adjacent gingival tissues. Keeping the bacterial load below the level that starts tissue loss has been the goal of periodontal therapy. This has been accomplished by debridement of the tooth surfaces and access surgeries.

The specific plaque hypothesis is being used to guide the treatment recently. This is based on research findings of the last 20 years, which indicate that most forms of periodontal disease appear to be specific bacterial infections. Findings of Walter J. Loesche et al indicate that about 90% of periodontitis patients have an anaerobic bacterial infection. An overgrowth of spirochaetes was seen associated with all forms of untreated adult periodontitis, early onset periodontitis, and localised juvenile periodontitis. Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola are present in high numbers in shallow and deep pockets in periodontal patients. Since P gingivalis, B forsythus, T denticola and spirochaetes are anaerobes, it is hypothesised that most forms of periodontal disease are anaerobic infections.

Anaerobic infections have been treated by antimicrobial such as metronidazole, because of a broad spectum of activity, which is specific for anaerobes. Walter J. Loesche reports that metronidazole seems to be the drug of choice because of its relative safety. Its most serious side effect is an Antabuse type of reaction, which may occur in a small percentage of individuals who drink alcoholic beverages. Another advantage of metronidazole is that clinical resistance by susceptible anaerobes has not been noticed even after 46 years of medical use.

Doxycycline is the second drug of choice, however, antibiotic resistant strains emerge more frequently with its use.

The propensity of clindamycine to cause ulcerative colitis in some patients makes it the drug of third choice.

Seven days course of metronidazole is to be given after completion of oral prophylaxis for more effectiveness, because, for a given dose of metronidazole, the results will be better if there are fewer bacteria on the tooth surfaces. After the systemic treatment with metronidazole, 62% reduction in the need for periodontal surgery has been reported.

A second round of antibiotic course for one week can be given if the improvement is marginal.

Walter J. Loesche et al report that after two courses of systemic treatment, if surgical need is still felt on recall appointment, they can be retreated with locally delivered 20% metronidazole in ethylcellulose strips, or 20% chlorhexidine in ethyl cellulose strips. Any teeth still in need of surgery or extraction after two rounds of systemic antimicrobial treatment and three rounds of locally delivered antimicrobials for one week each, should receive the necessary surgical procedure.

The dentists and patients can now have a treatment option in advanced forms of periodontal disease and consideration such as cost effectiveness may play a role in decision making.

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