Evaluation of the Effect of a Home-bleaching Agent on the Surface Characteristics of Indirect Esthetic Restorative Materials: Part I—Roughness

Abstract

Background Pressing esthetic demands of good looking make people undergo bleaching procedures. However, the effect of bleaching agents on esthetic restorative materials with different surface preparations has been poorly studied. Aim The aim of this study was to examine the effect of a homebleaching agent (carbamide peroxide: CP 38%) on the surface roughness of the polished fiber reinforced composite (FRC), overglazed, autoglazed, or polished ceramic samples. Materials and methods Twenty standardized cylindrical specimens were made of each of the following groups: overglazed, autoglazed, polished porcelain and also FRC. The test specimens exposed to the CP 38%, 15 minutes, twice a day for 2 weeks according to the manufacturer's recommendation. Six samples from each group were selected randomly to form negative controls. Surface roughness measurements (Ra, micrometer) for baseline, test and control specimens were performed by use of a profilometer. Paired t-test, Mann-Whitney test, and Kruskal-Wallis test were used for statistical analyses. Results The data showed that bleaching with CP 38% significantly increased the surface roughness of all the test samples (p < 0.05). The type of surface preparation caused significant differences between the susceptibility of porcelain subgroups to bleaching (p < 0.05). The polished porcelain specimens showed the highest changes after bleaching. Conclusion CP 38% significantly increases the surface roughness of the porcelains and FRC. The type of surface condition affects the amenability of the porcelain surface to the bleaching agent. Glazed porcelains were more resistant to roughness than the polished porcelains and also the composite. Clinical significance Roughening of porcelain and FRC occur following bleaching procedure. No special surface preparation of indirect esthetic restorative materials can completely preserve these materials from adverse effects of bleaching agents. How to cite this article Torabi K, Rasaeipour S, Khaledi AA, Vojdani M, Ghodsi S. Evaluation of the Effect of a Homebleaching Agent on the Surface Characteristics of Indirect Esthetic Restorative Materials: Part I—Roughness. J Contemp Dent Pract 2014;15(3):326-330.

The effect of bleaching on surface roughness and gloss of different CAD/CAM ceramic and hybrid ceramic materials

“…The mean surface roughness (Ra) values for different ceramics in ascending order were 0.42 (±0. 19) for LDS, 0.97 (±0.34) for ZLS, and 1.90 (±0.72) for PIC. Multiple linear regression showed that the overall regression was statistically significant (R 2 = 0.734, F = 10.9, and p < 0.001).…”

“…14 A number of studies showed that the effects of bleaching on surface properties such as surface roughness and microhardness of different ceramic materials are not significant. 11,[15][16][17][18] On the other hand, some studies have shown a significant negative effect on surface roughness, 13,14,[19][20][21][22][23][24] gloss, 14 and microhardness 25 suggesting that these restorations should be carefully protected during bleaching procedures. The effects concerning surface roughness have been shown to be influenced by the type of surface treatment of the ceramic prior to the bleaching treatment (e.g.…”