Do Oblique Cyclic Loads Influence the Tensile Strength of Different Morse Taper Connection Abutments?

Purpose: The purpose of this in vitro study was to evaluate the behavior of abutments attached to Morse taper connection implants, with and without internal index, against oblique cyclic loads. Materials and Methods: Twenty test pieces composed of abutments connected to Morse taper implants solely by friction action were subdivided into two groups (n = 10): group NI (no index) and group I (index). The test units were submitted to tensile tests, before and after cycling loads. Paired t tests were used for intragroup data at different times, and independent t tests were used for the comparisons between the groups. Results: There was a statistically significant difference in both the groups when the precycling and postcycling tensile values were compared. In the comparison between the no index and index groups, there was no statistically significant difference in precycling and postcycling tests. Conclusion: Within the limitations of this in vitro study, it can be concluded that the cyclic loads increased the tensile strength of abutments on Morse taper implants regardless of the index presence. On the other hand, the presence of an index did not significantly alter the values of tensile tests, before and after cyclic loads. Keywords: dental implant-abutment design, Morse taper dental implant-abutment interface, tensile strength