Available online 16 April 2024

Author links open overlay panel, , , AbstractStatement of problem

Optimal implant stability and preventing complications such as screw loosening are paramount concerns for implant-supported prostheses. However, studies examining the influence of various internal connection designs on detorque values and removal forces, critical aspects of implant success, are lacking.

Purpose

The purpose of this in vitro study was to assess the impact of the shape and design of the internal connection in tissue-level and bone-level implants on the detorque value and the force required for abutment removal from the implant.

Material and methods

Forty dental implants were securely mounted in 10×6×20-mm acrylic resin blocks positioned perpendicular to the surface. The implants were divided into 4 groups (n=10): bone-level SM Torx, tissue-level PSI Torx, bone-level UF Hex, and tissue-level UF Hex implants. After exposure to a dynamic loading test at 31.2 N, 2 Hz and 106 cycles, measurements were made of both detorque values and removal forces. Statistical analyses, including 1-way ANOVA with a post hoc Tukey test and Kolmogorov-Smirnov test, were conducted to assess the results (α=.05).

Results

The differences in detorque values among the 4 groups were statistically similar (P=.087). In terms of removal force values, tissue-level PSI implants exhibited the highest values, while bone-level UF implants had the lowest values, with significant differences in the removal forces among the 4 groups (P<.001). Pairwise comparisons revealed significant differences among the groups (P<.001), except for the comparison between tissue-level PSI and bone-level SM implants (P=.108).

Conclusions

While detorque values remain consistent across implant types, the shape and design of the internal connection of implants has a significant impact on the removal force required for abutment detachment from the implant.

Section snippetsMATERIAL AND METHODS

This in vitro study took place at the Dental Materials Laboratory, Isfahan University of Medical Sciences, Isfahan, Iran in 2021. Based on the observed effect size of 1.25 in the study by Moris et al14 and aiming for a power of 80% while maintaining a significance level of α=.05, the minimum required sample size for all groups was calculated to be 40 specimens, 10 specimens for each group. Sample size calculations were performed using a software program (G*Power v3.0.1; Heinrich Heine

RESULTS

The Kolmogorov-Smirnov test determined the normal distribution of the variables (P>.05). The 1-way ANOVA test indicated that the differences in the mean detorque value among the 4 groups were statistically similar (P=.087). However, for the removal force of abutments from the implants, the 1-way ANOVA revealed a significant difference among the 4 groups (P<.001). The post hoc Tukey pairwise comparisons showed no significant difference in removal force between tissue-level PSI and bone-level SM

DISCUSSION

Careful selection of materials, screw coatings, and connection designs and the implementation of suitable treatment plans can effectively reduce the occurrence of abutment screw loosening.16

This study aimed to evaluate the influence of the shape and design of the internal connection in tissue-level and bone-level implants in 2 critical parameters. The detorque value was assessed to identify the design with minimal torque loss after mechanical loading and the force required for abutment removal

CONCLUSIONS

Based on the findings of this in vitro study, the following conclusions were drawn:

1.

No significant differences were observed in detorque values among the 4 implant-abutment connection designs.

2.

Significant differences were evident in removal force values between all groups, except in the case of tissue-level PSI and bone-level SM implants.

References (23)J. Duyck et al.Histological, histomorphometrical, and radiological evaluation of an experimental implant design with a high insertion torque

Clin Oral Implants Res

(2010)

View full text

Copyright © 2024 by the Editorial Council of The Journal of Prosthetic Dentistry. All rights reserved.