Comparison of the 3D triple-scan protocol and the impression replica technique for 3-unit tooth-supported fixed dental prostheses.

The aim of this study was to compare the fit measurements from the 3 D triple-scan protocol and the impression replica technique, by measuring the fit of three-unit tooth-supported fixed dental prostheses. The results from an earlier study using the triple-scan protocol were compared to results from the impression replica technique for absolute marginal gap, cervical area gap and internal gap. There were no differences for cervical area gap or internal gap, but for absolute marginal gap the impression replica technique obtained significantly smaller fit values. The impression replica technique and the triple-scan protocol may both be used to measure the fit of tooth-supported restorations. However, the scanner used for the triple-scan protocol must be able to obtain scan points at the outermost edge of the restorations when used for absolute marginal gap.