Analysis of resistance to fatigue between straight solid and anatomic abutments of Morse taper system

Análise da resistência à fadiga entre pilares retos e anatômicos do sistema cone Morse

Abstract

Background

The study of the phenomenon of fatigue is essential because implant failures usually are caused by this process.

Purpose

The objective of this study was to examine the fatigue resistance of straight and anatomical abutments joints that were submitted to cyclic loads.

Material and method

We used 37 Morse taper implants and 37 abutments, divided into two groups (n= 16: straight abutment, n= 21 anatomical abutment). The sets were submitted to cyclic loading (5 million) using servo-hydraulic equipment. Three sets from each group were subjected to bending tests to determine the maximum load resistance, which served as the parameter for comparison of the cyclic tests. We evaluated number of cycles, load and bending moment.

Result

Of the 31 abutments cyclically tested, 17 (54.8%) fractured in fewer than 5 million cycles; 8 (25.8%) of these were straight abutments, and 9 (29%) were anatomical. A total of 14 samples (45.2%) resisted the cyclic loading. According to Fisher's exact test, there was no difference between groups as the fracture.

Conclusion

Despite of the straight abutments have higher average load and bending moment on the anatomical, both types of abutments showed similar performance as the fracture strength in vitro.

Descriptors:
Dental implants; material resistance; mechanical phenomena