Effect of Different Light Sources and Enamel Preconditioning on Color Change, H2O2 Penetration, and Cytotoxicity in Bleached Teeth

Abstract

This study evaluated the effects of acid etching of the enamel and the combination of different light sources (halogen light, light-emitting diodes [LEDs], and LED/Laser) and the bleaching product on color change, penetration of hydrogen peroxide (H2O2), and cytotoxicity over time. The color change (ΔE) and the amount of H2O2 that permeated the tooth tissue were analyzed using a spectrophotometer. Cell metabolism and morphology were evaluated using the methylthiazol tetrazolium assay and scanning electron microscopy, respectively. The ΔE values and H2O2 permeation were not significantly different under any of the experimental conditions. Tooth whitening significantly reduced cell metabolism, regardless of whether a light source was used. Preconditioning the enamel did not influence the cellular metabolism in any group. In conclusion, combining the bleaching product with different light sources and/or preconditioning the enamel resulted in few significant changes in color, transenamel and transdentinal penetration of H2O2, or cytotoxicity and cell morphology.

Influence of different types of light on the response of the pulp tissue in dental bleaching: a systematic review

“…These articles were subjected to full-text evaluation that resulted in the exclusion of two articles [40,41]. Finally, 12 articles met the inclusion criteria and were included in this review [8,13,15,19,20,22,29,[42][43][44][45][46].…”

“…In addition, to accelerate the bleaching process, protocols were proposed whereby bleaching was activated by different types of light [19,20], such as halogen light, light-emitting diodes (LED), or LED/laser [21,22]. Indeed, the light heats the bleaching gel, which generates a faster dissociation of HP and increases the release and penetration of ROS [21].…”

Effect of Dental Pigmentation Intensity on the Transenamel and Transdentinal Penetration of Hydrogen Peroxide

“…Next, the blocks were placed into artificial pulp chambers (19,20) (APCs), which were composed of two compartments. The upper compartment had an 8-mm aperture diameter at the bottom and another portion with a 6-mm aperture, allowing adaptation to the specimen.…”

Aferição do pH de diferentes agentes clareadores indicados para o clareamento intracoronário

“…O perborato de sódio (PbS) é um agente oxidante em pó, que, na presença de um ácido ou veículo aquoso, decompõe-se em metaborato de sódio, H 2 O 2 e oxigênio 6 . Embora seja uma opção consagrada no clareamento intracoronário, o PbS pode ser substituído pelo percarbonato de sódio (PcS), agente oxidante originado da reação entre H 2 O 2 e carbonato de sódio, muito empregado na indústria química e têxtil 10,11 . No entanto, poucos são os estudos que referenciam ou avaliam o PcS como um agente clareador dentário intracoronário 12 .…”

“…Os materiais avaliados foram acondicionados em frascos plásticos de armazenamento de filme fotográfico, com tampa e de cor escura, para PcS + H 2 O 2 foram mais efetivas que a mistura PbS + H 2 O no clareamento de dentes despolpados10 ; no entanto, mais estudos são necessários para avaliar o uso do PcS como agente clareador intracoronário e, em especial, a longevidade dos dentes clareados e os resultados imediatos obtidos6,12 .…”