Comparative Analysis of Screw Loosening Between Synocta and Inocta Tissue Level Abutments: An in Vitro Study Publisher



A Fathi AMIRHOSSEIN ; E Esmaeilian ERFAN ; S Salehi SEPIDEH ; R Mosharraf RAMIN ; R Atash RAMIN
Source: European Journal of Dentistry Published:2025

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). © 2025 Elsevier B.V., All rights reserved.