目的

探讨狗戴用纯钛、钴铬钼合金、镍铬合金三种铸造全冠后对其颊黏膜上皮细胞DNA损伤的情况。

方法

给狗分别进行纯钛、钴铬钼合金、镍铬合金三种铸造全冠修复，建立实验动物模型。采用IRIS Intrepid 型电感耦合等离子体原子发射光谱仪检测戴冠前、戴冠2 周、1 个月、2 个月及3 个月时颊黏膜上皮细胞中金属离子的种类和浓度， 同时应用彗星电泳方法检测颊黏膜上皮细胞DNA 损伤情况。 采用方差分析以及Spearman 等级相关进行统计学分析。

结果

戴用纯钛全冠后，各实验阶段狗颊黏膜上皮细胞中金属离子浓度以及彗星数目变化差异无统计学意义（P＞0.05）；戴用钴铬钼合金全冠后，铬与钴离子浓度随着时间逐渐升高， 其中戴冠2 周、1 个月及2 个月各时间段间离子浓度差异有统计学意义（P＜0.01），戴冠3 个月与2 个月之间差异无统计学意义（P＞0.05），而钼离子浓度在戴冠前后差异无统计学意义（P＞0.05）；戴用镍铬合金全冠后，铬、镍及铍离子浓度随着时间逐渐升高，其中戴冠2 周、1 个月及2 个月各时间段间离子浓度差异有统计学意义（P＜0.01），戴冠3 个月与2 个月之间差异无统计学意义（P＞0.05）。 而钼与铝离子浓度在戴冠前后没有明显变化（P＞0.05）。

结论

纯钛、钴铬钼合金全冠戴用后没有引起狗颊黏膜上皮细胞DNA 的损伤，而戴用镍铬合金全冠后，狗颊黏膜上皮细胞DNA发生明显损伤。

Objective

To study the corrosion behavior of three kinds of dental casting alloys and investigate the DNA damage of dog buccal mucosal cells caused by the released metal ions.

Methods

Three kinds of commonly-used dental casting alloys （pure Ti， Co-Cr-Mo and Ni-Cr） were used to make full crowns for dogs. The type and concentration of the released metal ions were measured by ICP-AES 2 weeks， 1 month， 2 months and 3 months after restoration. The DNA damage of buccal mucosal cells was studied by SCGE. Data were statistically analyzed by analysis of variance （ANOVA） and Spearman correlation.

Results

The metal ions released from Co-Cr-Mo and Ni-Cr were detected in buccal mucosal cells while the amount of the ions released from the pure Ti was too small to be detected. The DNA damage of mucosal cells increased with time after restoration of Ni-Cr crowns.

Conclusions

Pure Ti was the most corrosion-resistant among the three alloys. Pure Ti and Co-Cr-Mo showed no cytotoxicity.Ni-Cr alloy was prone to corrode and has cytotoxicity.