Periodontal Pocket Treatment in Beagle Dogs Using Subgingival Doxycycline From a Biodegradable System. I. Initial Clinical Responses

T he present study evaluated the clinical response of periodontal pockets in beagle dogs after treatment with a biodegradable delivery system containing 10% doxycycline hyclate (ABDS‐D). Eight adult, female beagle dogs had generalized, severe periodontitis with plaque and calculus‐laden pockets. In each animal, 3 teeth with multiple pocket sites ≥ 4 mm (mean depth = 6.0 mm) associated with attachment loss (mean = 5.4 mm) and which bled on probing (mean score = 2.5) were treated with a single application of either ABDS‐D (experimental group) or the delivery system alone without the doxycycline (control group). Residual polymer was removed at day 7. Bioassay of doxycycline in gingival crevicular fluid associated with presence of ABDS‐D gave mean levels of bioactivity of approximately 250 μg/ml. Levels of bioactive doxycycline were detected for approximately 7 days after ABDS‐D removal. Periodontal maintenance consisted of thrice‐weekly toothbrushing the treated sites. Clinical responses were evaluated at 2 weeks, and at bi‐weekly intervals thereafter for 4 months. Analyses of the data from the control group showed that there was only slight clinical improvement. In contrast, in the experimental group, bleeding on probing and probing depths were significantly reduced from baseline at all post‐treatment time points. At 1 month, mean probing depth reduction was 2.4 mm and this was maintained at 4 months (mean reduction = 2.5 mm). These probing depth reductions occurred primarily through gain of clinical attachment which was 2.0 mm at 4 months. Bleeding had been virtually eliminated (mean = 0.2). It was concluded that, for the beagle dogs with severely infected periodontal pockets in this study, treatment with subgingival doxycycline using the delivery system resulted in substantial improvement in periodontal health. J Periodontol 1996;67:1176–1184 .