Evaluation of the shear bond strength of resin cement to enamel after bleaching with Er: YAG and diode laser

Abstract

Objective: The shear bond strength (SBS) of composite resin cement and color change to enamel bleached with two different concentrations of hydrogen peroxide (HP) bleaching agents in combination with two different laser applications was evaluated. Materials and Methods: The Er: YAG laser ( λ = 2940 nm) and diode laser ( λ = 940 nm) were used with the bleaching agent consisting of 40% HP opalescence (Opalescence Xtra Boost, Ulgen, South Jordan, UT, USA) and 35% HP whiteness (Whiteness HP Blue, FGM Dental Products, Joinville, SC, Brazil). Seventy-two human extracted teeth were randomly divided into two groups: For the 40% HP treatment, 36 specimens were divided into three subgroups: (1) HP agent with no laser treatment, (2) HP agent treated with Er: YAG laser, and (3) HP agent treated with diode laser. The same protocol was performed for the 35% HP. The color change was analyzed using the Commission Internationale de l’ Eclairage (CIE) L* a* b* system and surface roughness was analyzed by an atomic force microscope. The specimens were bonded with resin cement and a shear bond test was performed at 0.5 mm/min. The failure surfaces were evaluated using scanning electron microscope analysis. Results: Δ E value of the 40% HP + Er: YAG group was significantly higher than the other groups while diode groups showed the lower SBS values than the control groups ( p < 0.05). Conclusions: The Er: YAG laser with 40% HP may be effective for the brighter teeth and the use of Er: YAG laser produced higher adhesion between enamel and resin cement than diode laser.

Bond strength of composite resin to bleached enamel after surface treatment with laser activated sodium ascorbate: An in vitro study

“…In contrary to the findings in this study some studies advocate the use of Er:YAG laser on tooth surface to enhance the adhesion to composite resin with the use of acid etching 18 . The better shear bond strength values obtained in other few studies could be because of deferment in restoration process by 14 days [3,6,9] . According to the results in this study, Er:YAG laser activation resulted in a slightly better shear bond strength than diode laser though it was not statistically significant.…”

“…According to the results in this study, Er:YAG laser activation resulted in a slightly better shear bond strength than diode laser though it was not statistically significant. The temperature rise during bleaching with Er:YAG laser is confines within the gel unlike in the case of diode laser which is weakly absorbed by the gel [6] . So this might have caused increase in enamel surface temperature with diode laser activation leading to changes in surface morphology resulting in reduced shear bond strength.…”

“…Hydrogen peroxide is the most routinely used bleaching agent. Hydrogen peroxide is a very unsteady molecule which diffuses through the organic matrix of enamel and dentin and releases free radicals and interaction between organic matrix and free radicals can unfavorably affect bond strength to enamel and dentin [6][7][8] . Bleaching treatment is usually recommended for discoloured tooth and also prior to adhesive esthetic restoration procedures.…”

The Effect of Two Different Wavelengths of Diode Laser on the Shear Bond Strength of Composite to Dental Enamel after Bleaching Process: An In Vitro Study

“…Research shows that bleaching with radiation is more effective than bleaching without any radiation [6,13,14]. Laser radiation weakens the enamel to composite bond strength because of the structural changes to the enamel [8,10,14,15]. Some of the different radiation devices used in bleaching emit a single specific wavelength called a laser [8,15], while others emit a range of wavelengths, like the QTH (quartztungsten-halogen) light-curing device, which emits a 380 to 520 nm light [8].…”

“…Research shows that bleaching with radiation is more effective than bleaching without any radiation [ 6 , 13 , 14 ]. Laser radiation weakens the enamel to composite bond strength because of the structural changes to the enamel [ 8 , 10 , 14 , 15 ].…”