Comparison of shear bond strength of orthodontic stainless-steel brackets on temporary crowns fabricated by three different methods: An in vitro study.

BACKGROUND AND AIMS: Different methods are available for making temporary restorations. The purpose of this study was to determine and compare the shear bond strength of orthodontic brackets on temporary crowns made by three different methods. MATERIALS AND METHODS: In this experimental study, disc form samples (N=54) were made in dimensions 8x1mm, according to the manufacturer's instructions. In this study, we had three groups (N=18) based on manufacturing methods (3D printing, conventional, and CAD/CAM). Following surface preparation of the samples, the brackets were bonded in the centre of the discs. Before the shear bond strength test, the samples were subjected to the thermocycling process. The shear bond strength of brackets was measured by Universal Testing Machine. Data were analysed by one-way ANOVA and LSD post hoc test. RESULTS: The findings indicated that the mean shear bond strength of orthodontic stainless-steel brackets on temporary crowns varied between CAD/CAM and 3D printing methods (P<0.001) and also between CAD/CAM and conventional methods (P<0.001). The mean shear bond strength of orthodontic stainless steel brackets on temporary crowns was not different between 3D printing and conventional methods (P=0.7). CONCLUSION: The shear bond strength of orthodontic stainless-steel brackets bonded to temporary crowns fabricated by conventional and 3D printing methods was similar, and the shear bond strength in the samples fabricated by CAD/CAM method was lower than other specimens.