Relationship between bacterial contamination and alveolitis after third molar surgery.

The frequency of alveolitis after third molar surgery was studied in three groups of 40 patients each. One group was premedicated with penicillin V, another with scopolamine, and the third group received no premedication. The respective frequencies of alveolitis were 5, 2.5 and 32.5 % (P less than 0.01 and P less than 0.001). The aerobic flora in blood sampled from the socket before suturing was significantly reduced (P less than 0.05) in the penicillin group as compared with the controls. In alveolar blood clot sampled 48 h postoperatively, both aerobes and anaerobes were significantly diminished (P less than 0.01). The concentration of penicillin V in alveolar blood ranged from 0.8 to 9.5 mg/l. The total bacterial content in alveolar blood before suturing showed poor correlation with the development of alveolitis. Abundant growth of aerobes was found, however, in 75 % of the patients with alveolitis, but in only 47 % of those without this complication.