1988 Fiscal Year Final Research Report Summary

Basic Research for Aetiology and Pathology of Periodontal Disease

Research Project

Project/Area Number	61480396
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	Conservative dentistry
Research Institution	Department of Periodontology,School of Dentistry,Aaichigakuin Universi (1987-1988) Tokyo Medical and Dental University (1986)
Principal Investigator	NOGUCHI Toshihide School of Dentistry,Aaichigakuin University, 歯学部歯周病学教室, 教授 (50014262)
Co-Investigator(Kenkyū-buntansha)	本多隆保愛知学院大学, 歯学部歯周病学教室, 講師 (40192322) KISHI Masayuki School of Dentistry,Aaichigakuin University, 歯学部歯周病学教室, 講師 (10183295) HONDA Takayasu School of Dentistry,Aaichigakuin University
Project Period (FY)	1986 – 1988
Keywords	Periodontal disease / Subgingival plaque / Chemical plaque control / Local drug delivery / 細菌 / 徐放性薬剤 / テトラサイクリン
Research Abstract	Based on the microbiological studies, it is well documented that the subgingival plaque, in which the gram-negative anaerobic rods are predominant, is associated with the destructive periodontal disease. In this investigation, we used hydroxypropylcellulose (HPC) as the base material and tried to apply the drugs directly to the subgingival plaque, the HPC containing 1% tetracycline (TC) formend solid and elastic strips. The in vitro release of the drugs from these strips showed almost 100% of this material added was released. From the clinical results obtained in this study, it was found that gingival index, probing depth and bleeding on probing tended to be less when the placebo strips were inserted. The results obtained from the microbiological studies showed that the TC containing HPC altered effectively the microbiological composition of the subginigival plaque. This new direct drug delivery system with HPC used as a base material was found to be effctive in changiang the composition of bacteria in the subgingival plaque and inproducing signs of clinical improvement. A note of caution should be added concerning the possible adverse in the subgingival flora which can be brought about by locally delivered tetracycline. Mandel et al. (1986) have shown that locally applied tetracycline in periodontal pockets infected with actinobacillus actinomycetemcomitans can actually result in a shift in the flora of such pockets to almost pure cultures of A. actinomycetemcomitans, associated with a period of active periodontal tissue destruction. It is likely that this results from re-seeding of the tetracycline-suppressed pocket by A.actinomycetemcomitans, which has invaded the gingival connective tissue and which remains viable in these tissue.