PERIODONTAL POCKET TREATMENT IN BEAGLE DOGS USING SUBGINGIVAL DOXYCYCLINE FROM A BIODEGRADABLE SYSTEM .1. INITIAL CLINICAL-RESPONSES

THE PRESENT STUDY EVALUATED the clinical response of periodontal pocke ts in beagle dogs after treatment with a biodegradable delivery system containing 10% doxycycline hyclate (ABDS-D). Eight adult, female beag le dogs had generalized, severe periodontitis with plaque and calculus -laden pockets. In each animal, 3 teeth with multiple pocket sites gre ater than or equal to 4 mm (mean depth = 6.0 mm) associated with attac hment loss (mean = 5.4 mm) and which bled on probing (mean score = 2.5 ) were treated with a single application of either ABDS-D (experimenta l group) or the delivery system alone without the doxycycline (control group). Residual polymer was removed at day 7. Bioassay of doxycyclin e in gingival crevicular fluid associated with presence of ABDS-D gave mean levels of bioactivity of approximately 250 mu g/ml. Levels of bi oactive doxycycline were detected for approximately 7 days after ABDS- D removal. Periodontal maintenance consisted of thrice-weekly toothbru shing the treated sites. Clinical responses were evaluated at 2 weeks, and at bi-weekly intervals thereafter for 4 months, Analyses of the d ata from the control group showed that there was only slight clinical improvement. In contrast, in the experimental group, bleeding on probi ng and probing depths were significantly reduced from baseline at all post-treatment time points. At 1 month, mean probing depth reduction w as 2.4 mm and this was maintained at 4 months (mean reduction = 2.5 mm ). These probing depth reductions occurred primarily through gain of c linical attachment which was 2.0 mm at 4 months. Bleeding had been vir tually eliminated (mean = 0.2). It was concluded that, for the beagle dogs with severely infected periodontal pockets in this study, treatme nt with subgingival doxycycline using the delivery system resulted in substantial improvement in periodontal health.