Novel nonmagnetic abutment designs for facial prostheses: an experimental study

Abstract

Background/aim: This in vitro study aimed to evaluate and compare the retentive forces of novel nonmagnetic abutment designs developed as an alternative to conventional magnetic abutments for facial prostheses.Materials and methods: A plexiglass model was constructed and two extraoral implants were placed in these blocks in a parallel position. Nonmagnetic abutments made of titanium were fabricated and screwed onto the implants. The nonmagnetic systems represent a novel design and include two different abutment designs (Type 1 and Type 2) with silicone attachments. Retentive force values for three abutment types: Conventional Magnetic System (CMS), Nonmagnetic abutment Type 1 System (NMS1), and Nonmagnetic abutment Type 2 System (NMS2) were measured at 0th, 120th, 360th, 720th, and 1440th dislodging cycles using a test machine. Given the data's distribution characteristics, non-parametric tests were used for analysis. The Kruskal-Wallis test evaluated significant differences among groups, followed by Dunn's post-hoc test for specific group comparisons. The Friedman test compared the number of dislodging cycles for each group, and the Benjamini-Hochberg adjusted Wilcoxon sign-rank test was used for pairwise comparisons.Results: Both NMS1 and NMS2 groups exhibited significantly higher retentive forces compared to CMS for each of the same dislodging cycles (p