Effect of In-Office Bleaching on Color and Surface Roughness of Composite Restoratives

Abstract

Objectives:The purpose of this study was to determine color changes and surface roughness of composites when they were subjected to in-office bleaching.Methods:12 discs 15 mm in diameter and 2 mm thick were prepared from two shades (A2 & A4) of two composites, Durafil VS (DF) and TPH3 (TPH). Specimens were polished and stored in distilled water for 24 hours at 37°C before being subjected to bleaching, staining, and re-bleaching. Each of the groups of specimens (DF-A2, DF-A4, TPH-A2 and TPH-A4) were subdivided into three subgroups (n=4) and bleached with Beyond, LumaWhite-Plus, and Opalescence-Boost. Specimens were then stained by immersing them in a coffee solution for 48 hours at 37°C, and then they were re-bleached. Colorimetric measurements were performed at baseline, after bleaching, after staining, and after re-bleaching. Surface roughness was determined with environmental SEM before and after bleaching. Data were statistically-analyzed.Results:None of the bleaching systems notably changed the color of composites (delta-E<2). Coffee staining affected DF specimens more than TPH. Stained specimens showed variable responses to whitening with no significant color change observed with TPH (delta-E<2) and significant changes observed with DF. Surface roughness significantly changed with bleaching, but the degree varied according to composite shade and bleaching agent.Conclusions:Three in-office bleaching agents had no significant color changes on two composites. DF showed more color change than TPH when immersed in coffee. Stained composites showed different degrees of whitening, with DF showing more response. Bleaching may adversely affect the surface texture of composites. Dentists should take into consideration that composite restorations may not respond to bleaching in the same way that natural teeth do.

Hydrogen peroxide bleaching induces changes in the physical properties of dental restorative materials: Effects of study protocols

“…In this study, no significant substance loss was observed after bleaching with the different protocols, which is consistent with the previous research . In agreement with previous studies, bleaching produced a rougher surface of the restorative materials tested, except for the ceramic. Moreover, a significant decrease in flexural strength was found for the polyacid‐modified composite after bleaching.…”

Changes in Optical Characteristics and Surface Topography of CAD/CAM Materials after Bleaching Applications: An AFM Evaluation

“…Increased surface roughness, which has been a major problem for clinicians and researchers, enhances discoloration and secondary caries with a biofilm accumulation as a consequence . The critical R a value causing biofilm accumulation was determined to be 0.2 µm .…”

“…When the bleaching procedure is applied, not only the teeth surfaces but also the surface of pre‐existing restorative materials come into contact with the bleaching agents. Although the bleaching procedure is demonstrated as safe and effective for dental hard tissues, it may not be safe for restorative materials which may be degraded or that have erosive characteristics . This may be explained by the absorption of chemical products through both the polymeric matrix and the matrix‐charge interface, which may cause the alteration of surface structure …”

“…Several studies have evaluated the effects of the bleaching agents on ceramics and composite resins. However, to the best of our knowledge, the available data regarding the effect of in‐office and at‐home bleaching on the optical and surface characteristics of resin nano‐ceramic and polymer‐infiltrated ceramic network CAD/CAM materials are limited.…”

Effects of home bleaching on surface hardness and surface roughness of an experimental nanocomposite

“…It was concluded that nanohybrid resins generally presented inferior properties compared to the nanofilled composite. [19] TPH 3 has 58% volume filler loading,[20] which is similar to Filtek Z350. The possible explanation for the significant reduction in the surface hardness might be due to the presence of Bis-GMA monomer.…”