Comparative evaluation of the effect of diode laser bleaching and led activated bleaching against chemical bleaching on color and micro leakage of class 5 restoration with nano hybrid composites an in vitro study

Abstract

Context: The effect of bleaching on tooth coloured restorative materials remains controversial, in terms of colour and tooth restoration interfaces. Few studies investigated affirming the action of different light sources used as an adjunct to in-office bleaching and its effect on recently introduced resin based composite restorations. This study focuses on the behaviour of nano hybrid composite exposed to Diode laser and LED bleaching techniques. Aims: The purpose of this in vitro study is to compare and evaluate the effect of Diode Laser and LED activated bleaching on colour and micro leakage of nano hybrid composites in Class V cavities.Methods and Material: Standardized Class V cavities were prepared on fifty freshly extracted human first maxillary premolar teeth, and restored with nano hybrid composite (Tetric N-Ceram). The samples were randomly divided into three groups and bleaching agent used is 40% Opalescence Boost (Ultradent) in all the three groups. Group 1 was activated with Diode laser (Picasso), Group 2 was activated with a blue hybrid LED (Bluephase) and Group 3 did not receive any light activation. Group 4- control group (unbleached restoration n=5). Restoration colour was measured before bleaching and after bleaching using VITA Compact Easy shade spectrophotometer and CIELAB values of ΔE, Δa*, Δb* and ΔL* were obtained. The same samples with the control group were subsequently immersed in dye solution of 2% Methylene blue and subsequently dye extraction technique was used to evaluate the micro leakage using spectrophotometer.Statistical analysis used: The results were subjected to ANOVA, Tukey and HSD tests (p3.3) in all the three groups. One-way ANOVA indicated no statistical difference in colour difference (p