How a 16% Carbamide Peroxide Home Bleaching Agent Affects the Surface Properties of Chairside CAD/CAM Materials?

Abstract

Surface changes of restorative materials after bleaching have clinical importance in terms of the durability and survival of restorations. This study aimed to evaluate the effect of home bleaching on the surface roughness, microhardness, and surface analysis of four different types of chairside computer-aided design and computer-aided manufacturing (CAD/CAM) materials. Specimens were prepared from composite resin (Brilliant Crios: BC), resin nanoceramic (Lava Ultimate: LU), polymer-infiltrated ceramic-network (Vita Enamic: VE), and zirconia-reinforced lithium silicate glass-ceramic (Vita Suprinity: VS) CAD/CAM materials. Specimens were polished using 800, 1000, 1200, and 2000 grit SiC papers. Each restorative material was randomly divided into two groups; control and bleaching (n=10). The 16% carbamide peroxide bleaching agent (Whiteness Perfect 16%, FGM) was applied to the specimens for 4 h/day for 14 days. Surface roughness values (Ra) were obtained using a profilometer, and microhardness values (VHN) were obtained using a Vickers microhardness test. Surface analysis of specimens was evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Data were analyzed Two-way ANOVA and Fisher’s Least Significant Difference (LSD) test (p<0.05). After bleaching, the surface roughness of BC (p<0.001) and VE (p<0.032) significantly increased. Bleaching did not significantly affect the microhardness of CAD/CAM materials. SEM evaluation showed material-dependent surface damages after bleaching procedures. The effect of 16% carbamide peroxide home bleaching agent on surface roughness and microhardness of chairside CAD/CAM materials is material-dependent. Before bleaching, restorative materials should be protected by applying a protective barrier and contact with the bleaching agent should be minimized. Also, after bleaching, the restoration surface should be carefully inspected, and re-polishing might be beneficial.

Changes in physical properties of universal composites andCAD/CAMmaterials after bleaching and antioxidant applications: Scanning electron microscope and atomic force microscope evaluation

“…Additionally, in the study by Serin‐Kalay and Zaim (2022), the R a values of LU increased after bleaching. However, no statistically significant difference was observed.…”

“…When examining studies in the literature that investigate the impact of bleaching agents on the microhardness values of restorative materials, varying results are observed (Kwon et al, 2010; Mohammadi et al, 2020; Serin‐Kalay & Zaim, 2022). In most of the studies considered, it was observed that these agents either did not statistically alter or reduced the microhardness values of the materials (Fernandes et al, 2020; Karatas et al, 2021; Mohammadi et al, 2020; Serin‐Kalay & Zaim, 2022). According to the results of our study, both bleaching applications caused a significant decrease in the microhardness values of all materials.…”

“…Serin‐Kalay and Zaim (2022) investigated how HB (16% CP) affected the surface properties of LU and different CAD/CAM blocks (n:10) (Brilliant Crios; BC, Vita Enamic; VE and Vita Suprinity; VS). According to the study results, the microhardness values of all materials decreased after bleaching, but no statistical difference was found.…”

Peroxide-Free Bleaching Gel: Effect on the Surface and Mechanical Properties of Nano- and Micro-Hybrid Restorative Composite Materials

“…HP is a powerful oxidant that produces free radicals and causes oxidation and has high reactivity and extensive ability to diffuse into an organic component of the composite [26]. Free radicals have the potential to impact the resin-filler interface and result in filler-matrix debonding [27]. In contrast, a statistically insignificant nanohardness reduction in the nanohybrid composite group might be explained by the lower resin matrix ratio and higher content of inorganic fillers in the composition.…”