The Study And Evaluation Of Tooth Bleaching By Peroxide

Objective Esthetics considerations have become much more important in modern dentistry. Several vital tooth bleaching systems have been introduced in response to the demand in esthetic dentistry. Peroxide bleaching is the most effective and efficient way to lighten and whiten tooth color in a short period of time. Though there are plenty of agent and light source combinations for choice, some of them are very expensive with unsure whitening effect and further effect to tooth structure.The purpose of this study is to evaluate the clinical efficiency of two bleaching agents, 15% hydrogen peroxide and 30% carbamide peroxide, combine with different light source. Possible alternations of tooth surface structure were also evaluated in this study. Spectrum distribution of bleaching agents and light sources were also measured. This study might serve as a reference for dentists to choose effective whitening systems with safety.Methods In the study, 45 people were divided into 3 test group, 15 people in each group were bleached with different bleaching agent and light source combinations as follows: Group A, 15% hydrogen peroxide with LED; Group B, 15% hydrogen peroxide with plasma arc; Group C, 30% carbamide peroxide with plasma arc. Color changes were measured with Vita shade guide and Shofu ShadeEye EX chromometer. Spectrum distribution of two bleaching agents and light sources were measured. All data of test were analysis with One-way ANOVA and Tukey HSD static analysis method.Results In the study, all bleaching group suffer significant clinical tooth whitening effect. The best whitening effect was found in Group A with average 5.61±2.93 color change (p<0.0001). To mild discoloration teeth (shade A & D group), the best whitening effect was found in the combination of 15% hydrogen peroxide and LED light source treatment (p<0.0001). To severe discoloration teeth (shade C group), the worst whitening effect was found in the combination of 30% carbamide peroxide and plasma arc light source treatment (p=0.01<0.05). There is no static significant difference of color change between maxilla and mandible (p=0.10>0.05). To difference tooth area, the best color changes was found in mandible canines (p=0.0167<0.05).The absorbtion spectrum distribution of 15% hydrogen peroxide is wider than 30% carbamide peroxide, from 300 to 800nm, and the peak value is about 320nm. The spectrum distribution of 30% carbamide peroxide is only from 280 to 600nm, and the peak value is about 310nm. The spectrum distribution of LED is from 420 to 540nm, and the peak value is about 470nm. The spectrum distribution of plasma arc is wider than LED, from 380 to 540nm, and the peak value is about 495nm.Conclusions These result suggest that all bleaching procedure used in this study could lead to significant whitening effect clinically, especially the combination of 15% hydrogen peroxide with LED. Special combinations of bleaching agents with light source may lead to more efficient clinical result. So, all bleaching combinations in this study can be safely used in clinic tooth bleaching treatment with cautions. To find effective bleaching agents combine with suitable light source may be the next step to develop more efficient, safer, and economic tooth bleaching technique.