Comparing the precision of reproducibility of computer-aided occlusal design to conventional methods

Abstract

Purpose: Reconstruction of patients' dental occlusion should be performed to fulfill esthetic and functional demands. These applied restorations should be in harmony with the existing occlusion and should not have any negative effects on intraoral dynamics. The aim of this clinical study is to compare the accuracy of the occlusal design shaped by conventional Wax Up methods and computer-aided design (CAD) regarding their similarity to the natural tooth morphology.

Methods: Impressions of 10 caries-free jaws were taken, and the resulting gypsum casts were scanned with a laboratory scanner. Preparations for all-ceramic full crowns were performed on second premolars and second molars. Occlusal design of 40, 3-member fixed partial dentures (FPD) were obtained with two different methods 10 FPD was designed with conventional wax up technique (Wax Up), 30 design was performed with CAD Dental wings open system (DWOS) software using three different anatomy libraries (Dental Wings (DW), Merz, Vita). The data of the bridges in the STereo-Lithography Interface Format (STL) was compared with the pre-cut data, which was regarded as a reference in terms of accuracy in the Atos so high end 3D digitizer.

Results: According to the results of Kruskal–Wallis test, there was no statistical difference between the Wax Up, Vita, Merz and Dental Wings groups (p > 0.05) when compared to the natural teeth. The main difference between all four groups and natural surface was 550 ± 130 μm.

Conclusions: Occlusal design produced by conventional techniques and CAM DWOS system compared to natural tooth morphology showed no statistically significant difference.