Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 20 0 2023 12 30 Composite Resin Bond Strength to Zirconia and Base Metal Alloys Using Two Types of Intraoral Porcelain Repair Systems 1 8 EN Mahnaz Arshad 1. Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran 2. Department of Prosthodontics, School of Dentistry, International Campus, Tehran University of Medical Sciences, Tehran, Iran Rasamedin Gordan Private Practice, Tehran, Iran Paniz Farrokhi Private Practice, Tehran, Iran Sareh Habibzadeh 1. Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran 2. Department of Prosthodontics, School of Dentistry, International Campus, Tehran University of Medical Sciences, Tehran, Iran 2022 07 10 2023 04 24 Objectives: This study aimed to evaluate the shear bond strength (SBS) of two repair composites (Crea.lign vs. PermaFlo) to a base metal alloy and zirconia ceramic. Materials and Methods: Sixty-four discs (12mm diameter, 1mm thickness) were fabricated using Wirobond base metal alloy and zirconia. They were then bonded with their respective composite resins (N=16) in each of the two porcelain chipping repair kit subgroups consisting of PermaFlo and Crea.lign. All specimens were stored in 37°C distilled water for 24 hours. Half of them were subjected to 10,000 thermal cycles (5-55°C, 30s). All specimens were tested for SBS with a universal testing machine. Failure types were analyzed using a digital camera. Analysis of the data was done by two-way ANOVA and Bonferroni post-hoc tests. Results: SBS was significantly affected by the type of composite resin. PermaFlo had a significantly higher SBS than Crea.lign to base metal alloy (P<0.001) and zirconia ceramic (P<0.001). Thermocycling decreased the SBS of both composites to base metal alloy (P<0.001) and zirconia (P<0.001). Conclusion: A universal adhesive could provide higher shear bond strength of zirconia and base metal alloy to composite resin than Crea.lign composite and the MKZ primer supplied by its manufacturer. https://fid.tums.ac.ir/index.php/fid/article/view/4537 https://fid.tums.ac.ir/index.php/fid/article/download/4537/2021