Several studies have indicated that the combination of
metronidazole and
spiramycin is synergistic against anaerobic bacteria and may be effective against oral
infections. The present study sought to determine the efficacy and safety of a commercial preparation of these two
antibiotics (
Rodogyl) when used adjunctively in the treatment of advanced
periodontal disease. In a double-blind parallel randomized trial, 56 patients (mean age = 44 years) with advanced
periodontitis (50 of whom completed the study) were assigned to either the
Rodogyl or placebo group. Both groups were thoroughly scaled and root planned for approximately 6 hours, with one group receiving
Rodogyl for 2 weeks and the other a placebo. No other
therapy was received during the study period. Two sites in each patient with probing depths of at least 7 mm were selected for study. Plaque level (P1I), gingival
inflammation (GI), probing depth (PD), and attachment level (AL) were measured at baseline, 14 days, 1 month, and then at monthly intervals up to 6 months. Subgingival bacteria were monitored with dark-field microscopy. The development of resistant bacteria, as well as side effects to the medications, was also monitored. The
Rodogyl group exhibited a greater gain in AL (0.67 mm) from the 2-month interval until the end of the study. Although this difference was statistically significant (P less than 0.05), it was not necessarily of
biologic significance. There was a significantly greater decline in the proportion of spirochetes in the
Rodogyl group at the 14-day interval, and this difference remained significant (P less than 0.05) at all study intervals. No difference in the proportion of motile organisms was observed.(ABSTRACT TRUNCATED AT 250 WORDS)