Comparison of Bleaching Products With Up to 6% and With More Than 6% Hydrogen Peroxide: Whitening Efficacy Using BI and WID and Side Effects – An in vitro Study

Abstract

The aim of this study was to evaluate the effect of bleaching agents containing different concentrations of hydrogen peroxide (HP) on color-change and on enamel-surface in bovine teeth. Furthermore the influence on cell viability and proliferation was investigated. Two hundred and forty teeth were randomly assigned into four groups (home bleaching ≤6%, in-office bleaching ≤6%, in-office bleaching > 6% HP, and control group). Bleaching was performed after artificial staining and the bleached index (BI) as well as the whiteness index (WI D ) was measured at several time points. Chemical analysis for HP concentrations and the pH of the bleaching products was done. Furthermore, enamel surfaces of randomly selected specimens were analyzed using scanning electron microscopy (SEM) and cytotoxicity of the tested bleaching products was evaluated in vitro using dental pulp cells (DPCs) and L929 cells. A statistically significant whitening effect was observed in almost all products. As expected all investigated products resulted in decreased cell viability, however, with different values of LC50 (median lethal concentration). SEM analysis showed an analog of enamel alterations with decreasing pH, increasing exposure time, and increasing HP concentration. Bleaching agents containing a low HP concentration are considered to be effective and to have less damaging effects on enamel and tested cells.

Three‐month evaluation of a low concentration (6% hydrogen peroxide) experimental bleaching gel containing Tio2 and chitosan: An in vitro study

“…Many studies, including the present study, have found the Philips Zoom bleaching system to be more effective than the Opalescence Boost PF bleaching system. [44][45][46] In addition, consistent with our results, Lee et al found a slight reduction in the color change after 1 month with both Philips Zoom and Opalescence Boost PF. 44 The Philips Zoom bleaching system exhibits high bleaching effectiveness because of a photoinitiator, ferrous gluconate, inside the gel, which accelerates the breakdown of HP due to UV light (Zoom Advanced Power) and provides effective bleaching by increasing the amount of OH radicals with the Fenton reaction.…”

Effects of bleaching gel containing TiO2 and chitosan on tooth surface roughness, microhardness and colour

“…18 However, the CIELAB formulation is widely used in many studies evaluating tooth colour. 9,16,43 For this reason, in our study the CIELAB and CIEDE2000 formulae were used together to evaluate colour change. Paravina et al 17 reported the perceptibility threshold ΔE ab = 1.2 and the acceptability threshold ΔE ab = 2.7 in the CIELAB system.…”

Effect of bleaching agents on hardness, surface roughness and color parameters of dental enamel

“…( 1 , 3 , 4 , 7 - 11 ). Approximately one third of CP decomposes to HP, which is the active agent of bleaching ( 1 , 4 , 8 , 9 , 12 ). Peroxides are unsTable substances that, in contact with dental tissues and moisture, release free radicals such as oxygen ions, which have the ability to diffuse through enamel and dentin and cause the oxidation of pigmented molecules that cause the tooth structure to darken ( 4 , 6 , 8 , 11 - 14 ).…”

“…Studies ( 1 , 4 ) have related that high concentration of CP and HP bleaching gels used for a shorter time did not show negative effects on enamel, while low concentration gels of peroxides caused changes on enamel surface such as decrease in its hardness and increased surface roughness. However, other studies ( 17 , 18 ) related that all the bleaching agents reduced the enamel hardness and increased the surface roughness, and that changes caused by products with high concentrations do not differ substantially from those caused by low concentrations, these discrepancies can occur due to different models of applied studies ( 4 , 9 ).…”

“…Bleaching effectiveness as well as the changes caused on enamel surface and side effects depends mainly on relationship established between the concentration of gel and its time of use, and may also be influenced by diffusion capacity of bleaching agent and its pH ( 4 - 6 , 9 , 11 , 14 ). The pH can change not only the bleaching efficacy, but it can also reduce the hardness, increase the roughness and cause the wear of tooth enamel ( 6 , 13 , 20 ).…”