[In vitro comparison of the retention adjustment of telescopic crowns].

Purpose: The objective of the present in vitro study is to explore the retention readjustment measure of the non-precious metal telescopic crown.

Methods: Twenty-seven standard size dies were divided into three groups randomly, conventional Co-Cr alloy group, Co-Cr alloy slit telescopic crown group and Au-Pd alloy group. Each group had 9 dies. The retentive force of telescopic crowns was investigated after repeated insertion/separation tests. Statistical analysis was performed using SPSS12.0 software package for one-way ANOVA.

Results: The retention of Au-Pd crown group and Co-Cr alloy slit telescopic crown was significantly larger than that of conventional Co-Cr alloy crown group. The maximal retention of Co-Cr alloy slit of the telescopic crown group was significantly larger than Au-Pd crown group. Compared with Co-Cr alloy slit telescopic crown group, the retention of all procedures in Au-Pd crown group had statistical significance except the retention of 800 procedures.

Conclusions: The retention of slit telescopic crown is similar to precious mental telescopic crown. Slit telescopic crown can compensate the retention deficient of none-precious metal telescopic crown. Supported by Science and Technology Research Project of Bureau of Health of Jiangxi Province (Grant No.060436).