Comparison of Tooth Color Change After Bleaching With Conventional and Different Light-Activated Methods

Abstract

Introduction:The demand for esthetic dental treatments is increasing in recent years mainly due to improved oral hygiene and better maintenance of oral health and teeth in older individuals. Bleaching of discolored anterior teeth is the most popular among esthetic dental treatments. Even individuals with sound teeth and adequate esthetics seek to have whiter teeth in the anterior region. The aim of this study was to evaluate tooth color changes following conventional in-office bleaching techniques compared to light-activated methods using different light sources. Methods: Seventy sound anterior teeth (devoided of caries and/or fracture), extracted for periodontal and orthodontic reasons were selected and allocated to 7 groups: (A) control, (B) conventional bleaching (C) LED-activated bleaching, (D) KTP laser-activated bleaching, (E) diode laseractivated bleaching, (F) Nd:YAG laser-activated bleaching and (G) CO2 laser-activated bleaching. Colorimetric evaluation was carried out before and after treatment using a spectrophotoradiometer. Data were analyzed by one-and two-way analysis of variance (ANOVA) as well as multiple comparison methods. Results:The results showed that all bleaching procedures were effective in reducing the yellowness index. However, the KTP laser-activated bleaching was significantly more effective than the other techniques in 95% confidence level. It was also seen that CO2 laser activated method has outperformed groups E, F and G and the conventional bleaching without light activation was not effective at all and represented similar results with the control group. Furthermore, the groups E and G had almost the same results in decreasing the yellowness index. Conclusion:The results showed that all bleaching techniques were effective however, the KTP laser-activated bleaching was significantly more efficient, closely followed by the CO2 laseractivated bleaching technique.

Effect of Three Wavelengths of Diode Laser on the Efficacy of Bleaching of Stained Teeth

“…In other words, laser irradiation leads to the release of free radicals from the bleaching agents in a shorter time. There was no difference in color change between different diode laser systems; this is in accordance with other studies [ 20 , 6 ]. However, in a study by Kiomarsi et al [ 6 ], conventional office bleaching yielded better results compared to laser bleaching; this may be due to the method of their office bleaching.…”

“…A spectrophotometer was used for colorimetry in our study, which is highly accurate and is commonly used for this purpose [ 20 ]. The CIE L*a*b* color parameters were measured in this study [ 21 ].…”

Color Stability and Staining Susceptibility of Direct Resin-Based Composites after Light-Activated In-Office Bleaching

“…While the nano-filled and sub-micron type specimens become dark after the bleaching procedure, the nano-hybrid and bulk-filled types specimens were brighter after bleaching ( Table 2 ), which is consistent with previous findings [ 16 , 24 ]. A similar trend was observed in the whiteness variations ( Figure 2 ).…”

“…The higher the HP concentration, the greater the de-pigmentation process, resulting in stain removal, and the color changes of RBCs [ 20 ]. Although the effects of HP on the color change of RBCs remain contentious, it is generally agreed that different types of resin-based composites reveal different resistances to bleaching [ 21 , 22 , 23 , 24 ].…”

Effect of an in-Office Bleaching Agent Containing Two Different Concentrations of Titanium Dioxide Nano Particles on the Color and Surface Roughness of Enamel.

“…The mechanism of bleaching is based upon the release of the reactive forms of oxygen, due to the contact between the peroxide and the tooth surface (3) . The oxygen reactive forms of low weight molecules permeate through the tooth structure through the inter-prismatic spaces where they act on and break long chain complex molecules into smaller chain ones causing a reduction in the rate of light absorption by the tooth structure with consequently teeth bleaching (4) .…”