Clinical Effects of Local Application of Poly (L-Lactic Acid) Microspheres Containing Tetracycline

Poly (L-lactic acid) microspheres containing tetracycline (TC-PLA-MS) were prepared using hydrophilic petrolatum or atelocollagen solution as the base. Clinical effects of the preparation were determined in 14 patients with periodontal disease after single administration to 57 sites involving periodontal pockets of more than 4 mm in depth. The results showed that bleeding on probing, total counts of anaerobic bacteria and the proportion of black pigmented bacteroides decreased significantly up to day 14 after administration in the TC-PLA -MS group, while, no significant difference was found in the probing depth, sulcus bleeding index and the proportion of spirochetes throught the study period. There was also no significant difference in the density of microorganisms in pockets between 200 1991.3. the TC-PLA-MS group and the controls after 7 days. No definite difference was noted in therapeutic effects between the different bases.