The Effect of Chemotherapy on The Local Environment in The Pocket

作为环境因素之一，在未经处理的牙周受累眼袋中测量了pH值。测定pH值与龈下菌群的关系。牙周袋的pH值范围为6.23~8.68，平均为7.66。低pH值袋的平均pH值为6.92，高pH值袋的平均值为8.53。革兰氏阳性菌，如链球菌和放线菌，约占从低pH值区域分离的细菌总数的60%。在高pH条件下，革兰氏阴性杆菌占分离细菌总数的60%左右。在pH为7.0的条件下，牙龈假单胞菌与粘性葡萄球菌或米勒葡萄球菌连续混合培养，在粘性葡萄球菌或米勒葡萄球菌的存在下，牙龈假单胞菌不能显示出足够的生长。牙龈假单胞菌和粘附性葡萄球菌微扩散室的pH在24小时后由7.0变为8.02，粘性葡萄球菌的pH为6.75。提示牙周病的发生可能与牙周炎的发生发展有关，牙周炎患者牙周组织中细菌群的变化与牙周袋pH值的变化有关。为评价pH值对抗生素敏感性的影响，用5种抗生素(四环素、美满霉素、强力霉素、四环素、美满霉素、多西环素、克林霉素和林可霉素对9株牙周炎相关细菌的最低抑菌浓度进行了测定。与四环素相比，多西环素和米诺环素的MIC值受pH值的影响较小。克林霉素的MIC值有降低的趋势。

The pH was measured in untreated periodontally involved pockets as one of environmental factors. The relation between pH and subgingival flora was determined. The range of pH in periodontal pocket was distributed between 6.23 and 8.68 and mean was 7.66. The mean ph of the low pH pockets was 6.92 and 8.53 in the high pH pockets. Gram-positive bacteria such as Streptococcus and Actynomyces comprised about 60% of the total isolated from the low pH pockets. In the pocket of high pH, gram-negative rods comprised about 60% of the total isolated bacteria. In the continuous mix culture of P.gingivalis and A.viscosus or S.milleri at pH 7.0, P.gingivalis did not show enough growth in the presence of A.viscosus or S.milleri. The pH in micro diffusion chambers for P.gingivalis and A.Viscosus was changed from 7.0 after 24 h. The pH in chambers for P.gingivalis was 8.02, pH 6.75 for A.viscosus.It is suggested that the antagonistic relationship between P.gingivalis and A.viscosus or Streptococcus may play a pathological role in theprogression of periodontal disease, and the change in bacterial flora in adult periodontilis was retated to the shift in pH in periodontal pockets.To evaluate the effect of pH on the susceptibility of antibiotics, 5 antibiotics (Tetracycline, Minocycline, Doxycycline, Clindamycin and Lincomycin) were analyzed by determinating their minimum inhibitory concentration against 9 periodontitis-associated bacterial strains. As for Doxycycline and Minocycline, the MIC values were less influensed by pH in comparison with Tetracycline. The MIC value of Clindamycin had a tendency to be less than that of Clindamycin.