This study aimed to evaluate marginal accuracy of titanium framework using different manufacturing techniques in fixed partial prostheses (Conventional casting, subtractive and additive manufacturing).
Material and Methods:Thirty resin replicas of a metallic master die were scanned. The design of the titanium framework was done utilizing 3Shape software (CAD) that resembles three-unit bridges to obtain Standard Tessellation Language (STL) file of the final design. Thirty titanium frameworks were fabricated and divided in to three groups according to manufacturing technique. Group C (n = 10): Casting manufacturing technique. Group S (n = 10): Subtractive manufacturing technique. Group A (n = 10): Additive manufacturing technique. In group (C), the framework wax pattern was fabricated using 3D printed wax pattern then invested and casted.In groups (S)and(A), The STL file of the final design of titanium framework was send to a computer aided manufacturing (CAM) machine and metal rapid prototyping machine. Each framework was luted to epoxy die under 2 kg static load. The luted assembly was segmented longitudinal at its center. The gap between die and framework was measured before and after sectioning at cervical shoulder in terms of vertical gap (VG) and horizontal discrepancy (HD), then were statistically analyzed by ANOVA/Tukey test (P < 0.05).
Results:The VG and HD values of titanium framework fabricated by subtractive technology showed high marginal accuracy compared to the others at all measurement locations. However, there was no statistical difference (P > 0.05) among the subtractive and additive technology. Casting titanium showed the least marginal accuracy in both VG and HD values.
Conclusion:The measured marginal accuracies of titanium framework fabricated by the subtractive and additive techniques demonstrated clinically acceptable marginal discrepancies on the working dies.