Does the index in Morse taper connection affect the abutment stability? An in vitro experimental study

PLoS One. 2024 Mar 8;19(3):e0298462. doi: 10.1371/journal.pone.0298462. eCollection 2024.

Abstract

The present study compared three different implant and abutment sets of type Morse taper (MT) connection, with- and without-index, were analyzed regarding their mechanical behavior without and with cyclic load application simulating the masticatory function. Ninety implant and abutment (IA) sets were used in the present study, divided into three groups (n = 30 samples per group): Group A, Ideale solid straight abutment (one piece) without index; Group B, Ideale abutment with an angle of 30-degree (two pieces) without index; Group C, Ideale abutment with an angle of 30-degree (two pieces) with index. The abutment stability quotient (ASQ) values, detorque value and rotation angle were measured before and after the cycling load. Twenty IA sets of each group were submitted to mechanical load at 360,000 cycles. The ASQ without load were 64.7 ± 2.49 for the group A, 60.2 ± 2.64 for the group B, 54.4 ± 3.27 for the group C; With load were 66.1 ± 5.20 for the group A, 58.5 ± 6.14 for the group B, 58.9 ± 2.99 for the group C. Detorque values were lower in groups B and C compared to group A (p < 0.05). In conclusion, the presence of the index did not influence the stability values. However, solid straight abutments (group A) showed higher values of stability compared to groups of angled abutments (groups B and C).

Grants and funding

Part of this work was supported by Ministry of Science and Innovation—Grant PID2020-116693RB-C21 funded by MCIN/AEI/10.13039/501100011033. The author Sergio Alexandre Gehrke was funded by post-doctoral grant n° 2021/PER/00020 from the Ministerio de Universidades under the program "Ayudas para la recualificación del sistema universitario español de la Universidad Miguel Hernandez" modalidad "Margarita Salas para la formación de jóvenes doctores". The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.