The effect of erbium family laser on tensile bond strength of composite to dentin in comparison with conventional method

Abstract

The purpose of this study was to evaluate the effect of Er:YAG and Er,Cr:YSGG laser on tensile bond strength of composite resin to dentine in comparison with bur-prepared cavities. Fifteen extracted caries-free human third molars were selected. The teeth were cut at a level below the occlusal pit and fissure plan and randomly divided into three groups. Five cavities were prepared by diamond bur, five cavities prepared by Er:YAG laser, and the other group prepared by Er,Cr:YSGG laser. Then, all the cavities were restored by composite resin. The teeth were sectioned longitudinally with Isomet and the specimens prepared in dumbbelled shape (n = 36). The samples were attached to special jigs, and the tensile bond strength of the three groups was measured by universal testing machine at a speed of 0.5 mm/min. The results of the three groups were analyzed with one-way ANOVA and Tamhane test. The means and standard deviations of tensile bond strength of bur-cut, Er:YAG laser-ablated, and Er,Cr:YSGG laser-ablated dentine were 5.04 ± 0.93, 13.37 ± 3.87, and 4.85 ± 0.93 MPa, respectively. There is little difference in tensile bond strength of composite resin in Er,Cr:YSGG lased-prepared cavities in comparison with bur-prepared cavities, but the Er:YAG laser group showed higher bond strength than the other groups.

Effects of Erbium Family Laser on Shear Bond Strength of Composite to Dentin After Internal Bleaching

“…This may lead to thermal damage, chemical changes and resistance to demineralization. 24 Although erbium laser groups in our study did not show bond strength values as high as those in the common procedure, erbium laser treatment of bleached dentin surfaces seems to offer promising results. In the current study, the effect of change in irradiation parameters on the results was not evaluated.…”

“…The family of erbium family lasers (erbium: yttrium-aluminumgarnet [Er:YAG] and erbium, chromium: yttriumscandium-gallium-garnet [Er,Cr:YSGG]) with 2 different wavelengths has been widely used for cavity preparation and dental surface conditioning in adhesive esthetic procedures. [20][21][22][23][24] Erbium family lasers have wavelengths corresponding to the peak absorption of hydroxyapatite and water and hence. This results in a water-mediated ablative effect.…”

“…Evaporation of water in the tissue leads to micro-explosions and ablation of tooth structure. 3,22,24,25 In other words, the increased internal pressure due to evaporation of water results in explosive ablation. 26,27 The ablative effect of the erbium lasers may be able to accelerate the release of free radicals and neutralize the effects of bleaching agents on bond strength.…”

Surface Treatment by Different Parameters of Erbium:Yttrium–Aluminum–Garnet (Er:YAG) Laser: Scanning Electron Microscope (SEM) Evaluation

“…It is thought that due to higher collagen matrix content of intertubular dentin, laser energy absorption and ablation rate is higher in the intertubular area, in comparison with the peritubular area. 3 It has to be noted that the application of Er:YAG laser for cavity preparation seems to be safe for pulpal tissue, as it just rises the temperature up to 3°C, which is lower than 5.5°C change which is the threshold tolerated by a tooth. 12 Other studies confirmed that the application of Er:YAG laser seems to be safe and induce a similar pulpal response, when compared with conventional bur drilling.…”

“…These wavelengths are absorbed by water and hydroxyapatite, so they are suitable for removing dental hard tissues, and produce no cracks or melting area. 3 Advantages of using Er:YAG laser instead of dental drill include making no noise or vibration, and producing open dentinal tubules on dental surface without any smear layer. However, some studies showed that morphological changes of enamel surface lased with Er:YAG do not create effective bond between composite and dental surface.…”