New method for local drug delivery using resorbable base material in periodontal therapy.

A new method for local drug delivery to the subgingival plaque was developed using hydroxypropylcellulose (HPC) as a base material. Using this material prepared in the form of strips containing antimicrobial drugs, the clinical and microbiological effects by this method on the human periodontal disease were studied. Before the clinical trials, the rate of the drug release from the strips was studied. Both drugs used in this study (CH: chlorhexidine and TC: tetracycline) were released almost within 2 hours from the strips in vitro. In the gingival crevicular fluid, however, it was found that the TC was maintained for 24 hours after the local delivery. Five patients who had deep pockets contralaterally were selected. The CH-containing HPC strips (5%) were applied in one pocket of each patient and the placebo strips were applied in other pocket on day 0, 2 and 4. Plaque Index, Gingival Index, probing depth and the presence or absence of bleeding on probing were recorded on day 0, 2, 4 and 6. Marked reduction of bleeding on probing was found in the pockets applied the CH-containing HPC strips. There was a significant reduction in the proportion of Bacteroides asaccharolyticus in these pockets (p less than 0.01).