Comparative analysis of intaglio surface trueness of cement-retained implant-supported prostheses generated by a cast-free digital workflow and a three-dimensionally printed cast workflow

Journal of Prosthetic Dentistry Published:September 27, 2022DOI:https://doi.org/10.1016/j.prosdent.2022.08.020 Abstract Statement of problem Comparative analysis of the accuracy of the prostheses produced by a cast-free digital workflow and 3-dimensional (3D) printing cast workflow is lacking. Purpose The purpose of the present investigation was to compare the intaglio surface trueness of implant-supported prostheses fabricated by using 3 different digital workflows: cast-free computer-aided design (CAD), 3D-printed cast CAD (direct insert), and 3D-printed cast CAD (indirect insert). Material and methods The laboratory data of 11 partially edentulous arches for prosthetic implant treatment were obtained. Three different workflows were tested to produce the cement-retained prostheses: cast-free CAD (Group CF), 3D-printed cast CAD with direct insert (Group PD), and 3D-printed cast CAD with indirect insert (Group PI). The intaglio surfaces of the prosthesis CAD data from Groups CF, PD, and PI were superimposed with 3D-printed prosthesis scan data from Group CF to measure 3D surface deviation. Using the prosthesis CAD data from Group CF as a reference, those from Groups PD and PI were compared by superimposition analysis. The root mean square (RMS) estimates, positive average deviations, and negative average deviations were measured. The Kruskal-Wallis test and Dunn test with Bonferroni correction, and the Wilcoxon rank sum test were used for statistical analyses (α=.05). Results Significant differences were found among the 3 groups when the 3D-printed prosthesis scan data were referenced (P<.05). Group CF showed the lowest RMS, positive average deviation, and negative deviation values, while Group PI showed the highest values. Significant differences in the RMS, positive average deviation, and negative average deviation values were found between Groups PD and PI when the prosthesis CAD data (Group CF) were referenced (P<.05). Conclusions Among the 3 different workflows tested, the prostheses generated from the cast-free CAD flow showed significantly lower intaglio surface deviation than those generated from the 3D-printed cast CAD flows, regardless of the insertion method of the implant replicas.