Microbiological evaluation of topical application of the controlled release strips containing ofloxacin (PT-01) in the human periodontal pocket

Abstract

The recognition that destructive periodontal diseases may be caused by specific microorganisms has led to an increased interest and usage of antimicrobial agents in periodontal therapy. In this study, the effect of topical application of ofloxacin (OFLX), a synthetic antibiotic, was microbiologically evaluated. The new developed controlled release strips containing OFLX (PT-01), in which there were structurally immediate- and sustained-releasing portions, were applied to the periodontal pockets of 27 adult subjects with periodontitis. Three different sites with a deep probing pocket depth (greater than or equal to 5 mm) were randomly selected in each patient, and were divided into three groups, i.e., PT-01 applied site (T), placebo-applied site (P) and control site (C). Periodontal treatments consisted of oral hygiene instruction and supragingival scaling on day 0 and 7, and subgingival scaling and root planing on day 14. PT-01 was weekly applied on day 0 to 35, and the subgingival plaque samples from each site were collected on day 0, 14, 21 and 42. The dynamics of subgingival microflora was investigated by dark field microscopy for determination of the %s of spirochetes, motile rods and coccoid cells, and anaerobic and aerobic cultivations for the determinations of the total number of subgingival bacteria, black-pigmented Bacteroides (BPB), Fusobacterium species and Actinobacillus actinomycetemcomitans. The results showed that the significant reduction of %s of spirochetes and motile rods and significant increase of % coccoid cells were found in only PT-01 applied sites during first 14 days. In this period, the total number of cultivable bacteria, BPB and Fusobacterium species were also significantly reduced in T sites. While, after subgingival scaling and root planing were performed, significant changes in the proportions and numbers of the subgingival microflora were found in all sites. Especially, PT-01 applied site showed significant improvement in the %s of spirochetes and motile rods as well as the total number of the bacteria. Moreover, the further microbiological determinations of the each isolate revealed that no detectable amounts of A. actinomycetemcomitans could be found from any samples in this study. These results suggested that weekly application of PT-01 in the periodontal pocket could have significant effects on the qualitative and quantitative improvements in the subgingival microflora. It was also suggested that the application of PT-01 might have ameliorating effect as adjuncts of mechanical subgingival plaque control in the periodontal treatment.