可摘局部义齿对基牙易发龋坏部位细菌组成变化的影响

The Effect of Removable Partial Denture on the Composition of Bacteria on the Apttodecay Site of Abutment Teeth

为探讨可摘局部义齿与基牙龋坏之间的潜在关系，对戴入可摘局部义齿后基牙易发龋坏部位早期的细菌组成进行了测定。结果：不同牙位在同一时期以及同一牙位的不同部位在不同时期的细菌检出百分比无显著性差异，球菌在初期较高，中期下降，后期上升，杆菌则相反。戴牙后７天、１４天、２１天和三个月细菌组成变化较大，但三个月后球菌和杆菌已恢复到常态指标。三种主要致龋菌均被检出，变形链球菌为优势菌，呈逐渐上升趋势，在７上的检出率较５高，差异有高度显著性（Ｐ＜０．００５）。粘性放线菌、乳酸杆菌检出率较低。由此提示，戴用可摘局部义齿可造成口腔微生态环境的改变，促进某些条件致龋菌的生长，成为基牙发生龋坏的潜在因素。

This study was aimed at the composition of plaques which were on the base teeth's carious sensitive sites, just after the insertion of the removable partial denture (RPD). The results showed that the ratios of bacterial detection in different teeth at the same period and those on the different sites of same teeth at different periods were not significantly different. There was a tendency that the detection ratio of the stomatococcus at the early period was higher than that of other bacteria, but at the middle period the ratios declined, and at the late period it was higher again. The detection ratio of the bacillus was on the contrary in the study. At the same time, the composition of the plaques changed significantly after the dentures had been used for 7, 14, and 21 days and 3 months. After 3 months, the ratios of the stomatococcus and the bacillas returned to their normal levels. The 3 main cariogenic bacteria were all detected in this study. The Streptococcus mutant was the dominant bacterium in the plaques and its ratio went up with the time duration. The ratio for the lower second molar was higher than that for the mandibular second premolar (P<0.05). The detection ratios of the Actinomyces viscosus and lactobacillus were lower. In conclusion, after the insertion of RPD, the oral microbial ecosystem would be changed and the cariogenic bacteria began to implant on the surface of the base teeth. So RPD is a potential factor to cause the caries.