Purpose: This study evaluated the effect of fatigue loading on the screw joint stability of a zirconium abutment connected to an external hexagon implant in vitro.
Materials and methods: Fifteen titanium and 15 zirconia abutments of 3 different heights (5, 8, and 11 mm) were connected to external titanium implants with titanium screws. A torque gauge was used to measure the reverse torque values before and after loading. An air cylindrical loading device was used to simulate mastication at a 45-degree angle to the longitudinal axis of the implant.
Results: There were significant differences (P<0.05) before and after the loading of titanium (5mm) and zirconia (5, 8, and 11 mm) abutments.
Conclusion: Zirconia abutments for external hexagon implants had durability rates similar to those of titanium abutments after repeating load on the reverse torque of the abutment screw, indicating that the zirconia abutment could be reliably used instead of the titanium abutment.
Keywords: External hexagon; Implant; Screw; Zirconia abutment.
Copyright © 2013 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.