Effect of Low Heat Steam Sterilization on the Volumetric Stability of Three Different 3D Printing Materials for Dental Implant Surgical Templates: An in vitro Study

Abstract

Background: Computer-guided surgical templates are considered critical instruments and are proposed to be sterilized before surgery. However, steam heat sterilization process may result in volumetric changes in the acrylic resin materials and this may compromise the accuracy of the drilling process during surgery. Objective: The aim of this in vitro study was to investigate the effect of steam heat sterilization on the volumetric and morphological dimensions of 3D printed surgical guides that could affect the accuracy of guided implant surgery. Methods: A total of fifteen templates of the same size and shape were printed from three different resin materials (five templates from each material) based on digital data of a clinical case previously planned with a special implant planning software. Following the printing procedure, all templates were digitally scanned using an intraoral scanner before and after steam heat sterilization at 121°C for 20 minutes. The scan data were saved in STL files and volumetric and morphological changes were evaluated before and after sterilization process by using appropriate software. Results: The results showed dimensional alterations within the three tested materials, before and after the sterilization process. Mean percentage of volumetric change was -1.53% for Visijet, 0.50% for MED610 and 1.9% for eResin. A larger deformation of the surgical guides at the sleeve and buccal wire areas was also observed. Conclusion: We can conclude that low steam heat sterilization seems to affect differently the three investigated implant template materials. Visijet and eResin showed a significant difference between the initial and the final volume of the surgical guides. This could possibly decrease the accuracy of computer guided surgery.