Accuracy of the Implant Replica Positions on the Complete Edentulous Additive Manufactured Cast.

Abstract

To compare the implant replica position accuracy on a duplicated complete edentulous maxillary implant definitive cast made either using conventional procedures or material jetting additive manufacturing (AM) technology using a coordinate measuring machine (CMM). A complete edentulous maxillary cast with 6 implant replicas was prepared. The definitive cast was duplicated using two manufacturing procedures namely conventional (CNV group) and additive manufacturing procedures (AM group). On the CNV, an AM Co-Cr framework and a custom AM custom tray with a polyether impression material were used to obtain an impression of the definitive cast at room temperature (23°C). On the AM group, the definitive cast was digitized using a laboratory scanner. The standard tessellation language (STL) file was exported and used to manufacture the polymeric AM specimens using a multijet printer following manufacturer´s recommendations. A new digital implant replica was located on each corresponding housing of each AM specimen. A total of 10 specimens per group was obtained. A CMM was selected to measure the position of each implant replica on the definitive cast, CNV, and AM specimens. Linear and angular discrepancies were computed for each specimen. Thus, the Mann Whitney U test was used to analyze the data (p = 0.05). There was no significant difference in x-, y-, and z- linear and XZ angular discrepancy between both groups. However, the AM group revealed a significantly higher median YZ angular discrepancy than the CNV group (p = 0.007). Material jetting AM technology demonstrated no significant difference in trueness and precision values of the linear and angular implant replica positions when compared to the conventional technique.