Retention influence of crowns cemented on implants with and without screw access

Mirella Aguiar de Freitas, Paulo Vicente Rocha

Introduction: In Implantology, the retention mechanism of the restoration to the intermediate can be cemented or screwed. The cemented one present difficult reversibility, however, the use of an access hole to the screw would allow such reversibility, combining the low cost of the components to the reversibility of the screwed prosthesis. Objective: The aim of this study is to evaluate the shear bond strength of prostheses on cemented implants, having or not access to the intermediate screw. Methods: Sixteen specimens were prepared (similar to regular implants, "Tiprep" intermediates (Bionnovation, São Paulo / SP) and 16 metal crowns, of which 8 were for conventional crowns control (G1) and another 8 crowns were made with an access hole to the screw, trespassing the metal, being the experimental group (G2). The crowns were cemented with RelyX U100 (3M ESPE) and the specimens from the G2 had the opening of the channel restored with light cured composite resin Filtek Supreme XT (3M ESPE). Specimens were subjected to tensile test in a universal testing machine 24 hours after cementation. Results: G1 showed average of 191.075 N; G2 showed 161.280 N. Applied the nonparametric Kolmogorov-Smirnov test, the dependent variable followed normal distribution (p = 0.923) and, with the Student t-test, there was no difference statistically significant (p = 0.353) between groups. It was considered the level of significance of 5%, p = 0.05. Conclusions: Based on the analysis, it can be stated that the access hole to the screw does not compromise or decrease the retention of crowns.

Keywords: Cement. Retention. Implant-supported dentures. Reversibility.

How to cite: Freitas MA, Rocha PV. Retention influence of crowns cemented on implants with and without screw access. Dental Press Implantol. 2012 July-Sept;6(3):82-90.

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