Shanghai Key Laboratory of Stomatology, Shanghai Research Institute of Stomatology, Ninth People's Hospital, Faculty of Medicine, Shanghai Jiao Tong University, 200011 Shanghai, China.
BMC Infect Dis. 2010 Aug 17;10:241. doi: 10.1186/1471-2334-10-241.
Secondary caries is responsible for 60 percent of all replacement restorations in the typical dental practice. The diversity of the bacterial sources and the different types of filling materials could play a role in secondary caries. The aim of this study was to determine and compare the microbial spectrum of secondary caries biofilms around amalgam and composite resin restorations.
Clinical samples were collected from freshly extracted teeth diagnosed with clinical secondary caries. Samples were categorized into four groups according to the types of restoration materials and the classification of the cavity. Biofilms were harvested from the tooth-restoration interface using a dental explorer and after dilution were incubated on special agars. The bacteria were identified using the biochemical appraisal system. Statistical calculations were carried out using SPSS11.5 software to analyze the prevalence of the bacteria involved in secondary caries.
Samples from a total of four groups were collected: two groups were collected from amalgam restorations, each had 21 samples from both Class I and Class II caries; and the other two groups were from composite resin restorations, each had 13 samples from both class I and class II caries. Our results showed: (1) Anaerobic species were dominant in both restoration materials. (2) In terms of the types of individual bacteria, no significant differences were found among the four groups according to the geometric mean of the detected bacteria (P > 0.05). However, there were significant differences among the detected bacteria within each group (P < 0.05). The composition of each bacterium had no statistical difference among the four groups (P > 0.05), but showed significant differences among the detected bacteria in each group (P < 0.05). (3) Among the four groups, there were no significant differences for the detection rate of each bacterium (P > 0.05), however, the detection rate of each bacterium within each group was statistically different among the detected bacteria (P < 0.05).
The proportion of obligatory anaerobic species was much greater than the facultative anaerobic species in the biofilm of secondary caries. Statistically, the materials of restoration and the location of secondary caries did not show any significant effects on the composition of the microflora.
继发龋占典型牙科实践中所有替换修复体的 60%。细菌来源的多样性和不同类型的填充材料可能在继发龋中起作用。本研究的目的是确定和比较银汞合金和复合树脂修复体周围继发龋生物膜的微生物谱。
从临床诊断为临床继发龋的新鲜拔出的牙齿中采集临床样本。根据修复材料的类型和腔室的分类，将样本分为四组。使用牙科探针从牙-修复体界面采集生物膜，经稀释后在特殊琼脂上孵育。使用生化鉴定系统鉴定细菌。使用 SPSS11.5 软件进行统计计算，分析涉及继发龋的细菌的流行情况。
共收集了四组样本：两组来自银汞合金修复体，每组均有来自 I 类和 II 类龋的 21 个样本；另外两组来自复合树脂修复体，每组均有来自 I 类和 II 类龋的 13 个样本。我们的结果表明：（1）两种修复材料中均以厌氧菌为主。（2）就个别细菌类型而言，根据检测细菌的几何均数，四组之间无显著差异（P>0.05）。然而，每组内检测到的细菌之间存在显著差异（P<0.05）。每组内每种细菌的组成无统计学差异（P>0.05），但每组内检测到的细菌之间存在显著差异（P<0.05）。（3）四组之间，每种细菌的检出率无显著差异（P>0.05），但每组内每种细菌的检出率在检测细菌之间存在统计学差异（P<0.05）。
在继发龋生物膜中，专性厌氧菌的比例明显大于兼性厌氧菌。统计学上，修复材料和继发龋的位置对微生物群的组成没有显著影响。
