Dimensional accuracy of different dental CAD software programs in fixed partial denture construction: An in vitro study.

Abstract

Statement of problem: Computer-aided design (CAD) software programs have become an integral part of prosthesis construction in digitally supported prosthodontics. Evidence regarding the accuracy of different CAD software programs is still inadequate.

Purpose: This study was conducted to evaluate the trueness and precision of 4 dental CAD software programs.

Material and methods: A single standard tessellation language (STL) file of 3 prepared abutment teeth was used to design 40 frameworks (N=40) of a 3-unit fixed partial denture (FPD) by using 4 dental CAD software programs (Dental System Premium, Ceramill Mind, Elefsina, and CEREC InLab), 10 frameworks each. Framework thickness was set to 0.6 mm, and connectors were 9 mm² in cross-section area. All designs were imported into a 3-dimensional (3D) analysis software program. Trueness and precision were evaluated in terms of marginal fit and its axial height, thicknesses of the cement gap and copings, and the cross-section areas of connectors. The 4 studied software programs were compared using 1-way ANOVA followed by post hoc Tukey tests. The thicknesses of the copings and cross-section areas of connectors were compared with set parameters using the 1-sample t test. Coping dimensions within each software program were compared using ANOVA with repeated measures followed by post hoc Bonferroni adjusted tests, and connectors cross-section areas were compared using the paired t test (α=.05).

Results: All software programs showed 0 µm at the margins of the frameworks. CEREC InLab showed the shortest axial heights of marginal fit (0.506 ±0.01mm). Dental System Premium and CEREC InLab showed an even cement gap of 80 µm, while Ceramill Mind and Elefsina showed 82 µm. CEREC InLab showed the highest average coping thickness (0.639 ±0.002 mm), while Dental System Premium presented the lowest average connector cross-section area (8.67 ±0.16 mm²). CEREC InLab was the only software program with insignificant differences between copings in the axial height of marginal fit. Dental System Premium and Elefsina showed insignificant differences between copings in average coping thickness. Dental System Premium and Ceramill Mind showed insignificant differences in connectors cross-section areas.

Conclusions: All studied software programs had an even 0-µm marginal fit with variable axial heights of the marginal fit for a 3-unit FPD framework. The 4 software programs showed close ranges of accuracy for the thicknesses of cement gaps and copings and cross-section areas of connectors. All software programs had acceptable clinical precision.