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CC BY 4.0 · Eur J Dent
DOI: 10.1055/s-0045-1808257
Original Article

Comparative Analysis of Screw Loosening between SynOcta and InOcta Tissue Level Abutments: An In Vitro Study

Amirhossein Fathi
1   Department of Prosthodontics, Faculty of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran
,
Erfan Esmaeilian
1   Department of Prosthodontics, Faculty of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran
,
Sepideh Salehi 
2   Department of Dentistry, Faculty of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran
,
Ramin Mosharraf
1   Department of Prosthodontics, Faculty of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran
,
Ramin Atash
3   Department of Dental Prosthodontics, Université Libre de Bruxelles, Brussels, Belgium
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Abstract

Objective

Implants are one of the common treatments in dentistry. This treatment has various complications such as inflammation around the implant, failure of the coating, and screw loosening. Several factors contribute to screw loosening, including abutment type and collar height. Therefore, this study aims to compare the amount of loosening in two types of abutments—InOcta and SynOcta abutments.

Materials and Methods

In this laboratory study, 20 titanium fixtures of the Dentis brand were divided into two groups. Each group consisted of 10 fixtures. The fixtures were mounted vertically in acrylic blocks with dimensions of 20 × 6 × 10 mm. After installing the SynOcta and InOcta abutments, the screws were torqued to 30 N·cm and re-torqued after 10 minutes. Subsequently, the samples were transferred to a chewing simulator. A compressive force of 90 N was applied for 10,000 cycles at a frequency of 75 rpm. After loading, the torque required to loosen the screws was measured, and the loosening torque was calculated. The data were analyzed using an independent t-test, and a significance level (p-value) of less than 0.05 was considered.

Results

The mean de-torque for the tissue level InOcta abutments was calculated to be 25.75 N.cm, while the mean de-torque for the SynOcta abutments was 21.98 N.cm. A comparison using the t-test showed that the mean de-torque for the InOcta abutment group was significantly higher than the SynOcta group (p < 0.001).

Conclusion

The final results of the experiments indicate that under laboratory conditions, the de-torque of the abutment screw in the tissue level SynOcta group is significantly lower than that in the InOcta group (p < 0.001).

Keywords

abutment - screw loosening - InOcta abutment - SynOcta abutment


Publication History

Article published online:
07 May 2025

© 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

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