对４２例共５０副覆盖义齿修复病例的１２１个覆盖基牙的龋发病情况，进行了三年的动态观察，并与这些义齿的１３４个其他基牙作对照、结果覆盖基牙龋发生率为３１．４％，其他基牙为３０．５９％，Ｘ２检验，Ｐ＞０．０５，无显著差异。采用三种方法处理覆盖基牙根面：光固化复合树脂覆盖、银汞合金覆盖和铸造钉盖覆盖，三者之间三年龋发生率比较，虽无显著差异，但银汞覆盖组龋发生率较高，尤其与树脂覆盖组比较Ｐ＝０．０７４１，接近显著界值。当义齿基托组织面与基牙不密合时，基牙的菌斑指数明显增高，龋发生率亦升高。上述结果表明：可摘部分义齿（包括覆盖基牙）修复后，可影响唾液自然流动，自洁作用下降，致使菌斑形成，继而基牙龋变；银汞合金覆盖之根面显示有较高的龋发生率；基托组织面与覆盖基牙的密合程度与其牙龋病关系密切。 Forty-two cases of caries of 121 covered abutments in 42 cases of overdenture repaired were dynamically observed for three years and compared with 134 other abutments of these dentures. The results showed that the incidence of caries in the abutment was 31.4%, other abutments 30.59%, X2 test, P> 0.05, no significant difference. Three methods were used to deal with the root surface of the abutment: photocurable composite resin covered, silver amalgam covered and cast nail covered, the incidence of three-year caries among the three groups was no significant difference, but the occurrence rate of caries in silver-mercury covered group Higher, especially compared with the resin covered group P = 0.0741, approaching a significant cutoff. When the denture base tissue surface and the abutment is not close, the abutment tooth plaque index was significantly increased caries incidence also increased. The above results show that the removable partial dentures (including overlying abutments) can affect the spontaneous flow of saliva and decrease the self-cleaning effect, resulting in the formation of plaque and then caries of the abutments; the root surface covered by the amalgam shows higher The incidence of caries; the degree of close contact between the surface of the base tissue and the abutment teeth is closely related to the dental caries.