The effect of Implant Abutment Connections on Abutment screw loosening(an in vitro study)

Abstract

Widespread use of dental implants as a predictable treatment choice has drawn attention to its complications as a major challenge despite its high clinical success rates. In this context, loosening of the abutment screw in posterior single crowns is the most common problem; use of adequate preload and proper anti-rotational features at implantabutment interface appear to be two main solutions to such a problem. The aim of the present study was to evaluate the effect of implantabutment connections in 4 different implant systems before and after cyclic loading. Materials and methods. In this study, Intra-Lock , Dentis , Xive and Dio implant systems were used. Each system underwent one million cycles of dynamic forces for eight times with the magnitude of 110 N. For each specimen after tightening the screw with a torque of 32 Ncm, the detorque values were measured and recorded by a digital torquemeter after and before cyclic loading. Data were analyzed by Kolmogorov-Smirnov, LeveneEs, One-way ANOVA and Tukey Post hoc tests. Results. Initial detorque values between the study groups showed significant differences (P<0.0001). Pairwise comparison showed significantly lower primary detorque values in the Dentis system compared to the three other systems (P<0.0001). After cyclic loading, significant differences between the study groups were observed (P<0.0001). Pairwise comparison of the groups showed significant differences between all the systems after loading. Conclusion. The type of the implantabutment connection is an important factor influencing the amount of abutment screw loosening