Biological Sciences and Health Center, Universidade Federal do Maranhão, São Luís, Brazil.
Caries Res. 2011;45(3):275-80. doi: 10.1159/000325854. Epub 2011 May 12.
The relationship between clinical characteristics of carious dentin and bacterial colonization after partial caries removal is not completely understood. The aim of this study was to compare microbial counts between categories of carious dentin color, consistency and humidity, and to evaluate the correlation between these characteristics and the presence of cariogenic microorganisms in deep cavities (2/3 or more of the dentin thickness) submitted to partial caries removal. Sixteen primary teeth were submitted to the removal of all carious tissue from the lateral walls of the cavity, whereas carious tissue of the pulp wall was removed superficially. Dentin in the pulp wall was classified according to color, consistency and humidity immediately after cavity preparation and 3-6 months after cavity sealing and a tissue sample was collected on the same occasion for microbiological evaluation. Before sealing, Streptococcus mutans (p = 0.033) and Lactobacillus spp. (p = 0.048) counts were higher in cavities with humid dentin compared to cavities with dry dentin. A negative correlation was observed between carious dentin consistency and S. mutans count during this phase (r(s) = -0.571; p = 0.020). Arrest of dentinal caries lesions was observed after sealing, which was characterized by a reduction of bacterial counts and changes in dentin color, consistency and humidity, irrespectively of baseline dentin characteristics. The clinical characteristics of carious dentin change after the period of cavity sealing and cannot be applied as absolute indicators to limit the excavation of carious dentin when minimally invasive techniques are used.
牙本质龋临床特征与部分去腐后细菌定植的关系尚未完全阐明。本研究旨在比较不同颜色、质地和湿度牙本质类别之间的微生物计数，并评估这些特征与深龋（2/3 或更多牙本质厚度）在部分去腐后是否存在致龋微生物之间的相关性。16 颗恒牙在侧壁进行了所有龋坏组织的去除，而牙髓壁的龋坏组织仅进行了表面去除。在窝洞预备后即刻和窝洞封闭后 3-6 个月，根据颜色、质地和湿度对牙髓壁的牙本质进行分类，并在同一时间采集组织样本进行微生物评估。在封闭前，与干燥牙本质相比，潮湿牙本质的变形链球菌（p = 0.033）和乳杆菌属（p = 0.048）计数更高。在该阶段观察到牙本质龋病变的进展，牙本质质地与变形链球菌计数呈负相关（r(s) = -0.571；p = 0.020）。在封闭后观察到牙本质龋的静止，这表现为细菌计数减少以及牙本质颜色、质地和湿度的变化，而与基线牙本质特征无关。窝洞封闭后牙本质龋的临床特征发生变化，因此不能将其作为在使用微创技术时限制去腐的绝对指标。
