Clinical and microbiological effects of initial periodontal therapy in conjunction with amoxicillin and clavulanic acid in patients with adult periodontitis - A randomised double-blind, placebo-controlled study

The aim of the present study was to investigate the clinical and microbiolo gical effects of initial periodontal therapy in conjunction with systemic a moxicillin plus clavulanic acid in adult periodontitis patients using a dou ble-blind, parallel-group, and placebo-controlled protocol. 21 patients wit h a clinical diagnosis of generalised adult periodontitis were recruited. C linical measurements and microbiological assessments were carried out at ba seline, 3, and 12 months posttreatment. Approximately 6 weeks after initial periodontal treatment (3-6 h), patients were randomly assigned to receive coded study medication of 500 mg amoxicillin plus 125 mg clavulanic acid (A ugmentin(R)) or placebo, every 8 h for 10 days. Patients returned for follo w-up visits 3, 6, 9, and 12 months after completion of the medication. The mean plaque index (PI) at baseline was 1.1 for placebo group and 0.9 for th e test group. At 3 months, the PI had dropped to 0.3 in both groups, and wa s maintained during the rest of the study. The changes in bleeding on probi ng (BOP) and gingival index (GI) in the course of the study were similar in both groups. The mean whole mouth probing pocket depth (PPD) in the placeb o group was 3.8 mm at baseline and 3.9 mm in the test group. A mean reducti on of 1.0 mm in the placebo group and 0.9 mm in the test group was observed during the first 3 months. No further reduction in PPD was noticed during the study period in either group. There was no statistically significant di fference in the PPD reduction between the 2 groups. The change in clinical attachment level (CAL) from baseline to 3 months amounted to 0.5 mm in both groups. Between 3 and 12 months, the CAL changed in neither group. In both groups, treatment resulted in a decrease in the number of spirochetes and motile rods in positive patients, but no significant differences between ei ther group were noted in any of the dark field microscopy observations. At baseline, 1 patient in the placebo group and 2 patients in the test group w ere culture positive for Actinobacillus actinomycetemcomitans (Aa). After t herapy Aa was not detectable in the placebo group and 1 patient remained po sitive in the test group. In the placebo group, the number of patients posi tive for Porphyromonas gingivalis (Pg) decreased from 7 to 2 after therapy. In the test group, the 4 patients positive for Pg at baseline remained pos itive after therapy. In both groups, all subjects were positive for Prevote lla intermedia (Pi) and Fusobacterium nucleatum (Fn) at baseline. At 12 mon ths, all subjects had detectable subgingival Fn. 9 out of the 11 placebo an d 8 of the 10 test patients remained positive for Pi. There were no differe nces in detection frequency of Peptostreptococcus micros (Pm) and Bacteroid es forsythus (Bf) in both groups between baseline, 3, and 12 months post-tr eatment. The findings demonstrated that, in comparison to placebo, systemic amoxicillin plus clavulanic acid provided no additional clinical and micro biological effects in the treatment of adult periodontitis patients.