Objective: The aim of this study was to obtain the reasonable thickness of Ti-Zr alloy used for denture base material.
Methods: According to the "Revised ADA Specification No. 12 for denture base polymers", the transverse deflection tests of Ti-Zr alloy after casting were performed. Pure titanium, Ti-6Al-4V alloy and Co-Cr alloy were examined as the control. Three groups of wax patterns with different thickness were designed. Ti-Zr alloy, pure titanium and Ti-6Al-4V alloy were casted into molds at 300 degrees C, which were made of zircon (ZrO2.SiO2) investment, using a casting machine (China), with a program of vacuum, pressure and centrifuge casting. Co-Cr alloy was casted by normal method in clinic. The transverse deflections of these four alloys castings with three different thicknesses were measured using a transverse testing machine.
Results: When the thickness is 0.65 mm for Ti-Zr alloy, pure titanium and Ti-6Al-4V alloy, and 0.57 mm for Co-Cr alloy, the transverse deflections could satisfy the requirement.
Conclusion: The transverse deflection is one of the key indexes for evaluating the ability of dental material to bear biting forces. The reasonable thickness of Ti-Zr alloy used as denture base material is 0.65 mm.