Secondary caries is a disease that occurs on the tooth after the filling has been used for a period of time. Secondary caries is also the main reason for the replacement of dental restorations. Regardless of the material used for fillings, secondary caries cannot be completely avoided. The proportion of secondary caries is very high after filling in permanent teeth or primary teeth. Secondary caries mainly occurs because of the formation of micro cracks after filling. When the micro crack width exceeds 50 microm, saliva will enter the micro cracks between the filling and tooth tissue. The cariogenic bacteria in the saliva will grow when the environment of micro cracks is appropriate, thereby producing secondary caries. The prevention of secondary caries includes micro crack control, fluoride use, teeth cleaning, tooth decay and gum disease treatment, and regular checkups.
继发龋是充填体在使用一段时间后在牙体组织所发生的龋病，它伴随着充填的产生而产生，是修复体被替换的主要原因。目前，无论选择何种充填材料都不能完全避免继发龋的产生。无论恒牙还是乳牙，充填后发生继发龋的比例均较高。发生继发龋的原因很多，最主要的原因是充填后微裂隙形成，当微裂隙宽度超过50 µm时，充填体与牙体组织之间会有微量的唾液进入，唾液中存在致龋微生物，当微裂隙的环境合适时，致龋微生物就会生长繁殖，产生继发龋。预防继发龋可以从几个方面着手，包括控制微裂隙，局部使用氟化物，清洁牙齿，治疗龋病和牙周病以及定期检查等。