Aim: To compare the effect of erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser at different irradiation parameters and acid etching on the shear bond strength (SBS) of orthodontic brackets to enamel. Materials and methods: Forty bovine incisors were randomly distributed into groups (n = 10): GI: 37% phosphoric acid etching; GII: Er,Cr:YSGG laser etching 19.1 J/cm2; GIII: Er,Cr:YSGG, 29.3 J/cm2; and GIV: Er,Cr:YSGG, 42.4 J/cm2. After treatments, metallic brackets were bonded using Transbond XT adhesive system. After light curing, the samples were subjected to 500 thermal cycles, debonded with a universal testing machine, and the SBS values were recorded. After debonding, surface morphology was evaluated using scanning electron microscopy (SEM) and optical coherence tomography (OCT). The values of SBS testing were analyzed by one-way analysis of variance (ANOVA) and Tukey post hoc test, at 5% significance level. Results: The mean SBS values of GI, GII, GIII, and GIV groups were 6.2 ± 1.7 MPa, 4.6 ± 2.5 MPa, 7.0 ± 2.2 MPa, and 8.0 ± 3.6 MPa, respectively. Laser irradiation promoted rough surfaces in all parameters used, and the OCT analysis revealed higher optical changes on lased groups when compared with phosphoric acid. Conclusion: Er,Cr:YSGG laser irradiation operated at 42.4 J/cm2 and 29.3 J/cm2 is a better alternative for etching enamel prior to the orthodontic treatment than the phosphoric acid. Clinical significance: Er,Cr:YSGG laser irradiation is better than the phosphoric acid for etching enamel prior to the orthodontic treatment because laser irradiation promotes similar SBSs and preventing demineralization around orthodontic brackets.
Kim JH, Kwon OW, Kim H, et al. Acid resistance of erbium-doped yttrium aluminum garnet laser-treated and phosphoric acid-etched enamels. Angle Orthodontist 2006;76(6):1052–1056. DOI: 10.2319/11405-398.
Pashley DH. The effects of acid etching on the pulpodentin complex. Operative Dent 1992;17(6):229–234.
Horiuchi S, Kuroda S, Hiasa M, et al. Reinforcement of bond strength of self-etching orthodontic adhesive. Angle Orthod 2012;82(1):30–35. DOI: 10.2319/012011-39.1.
Stern RH, Sognnaes RF. Laser beam effect on dental hard tissues. J Dent Res 1964;43:873–873.
Kohns P, Zhou P, Störmann R. Effective laser ablation of enamel and dentine without thermal side effects. J Laser Appl 1997;9(3):171–174. DOI: 10.2351/1.4745457.
Basaran G, Ozer T, Berk N, et al. Etching enamel for orthodontics with an erbium, chromium:yttrium-scandium-gallium-garnet laser system. Angle Orthod 2007;77(1):117–123. DOI: 10.2319/120605-426R.1.
Lee BS, Hsieh TT, Lee YI, et al. Bond strengths of orthodontic bracket after acid-etched er:YAG laser irradiated and combined treatment on enamel surface. Angle Orthod 2003;73(5):565–570. DOI: 10.1043/0003-3219(2003)073<0565:BSOOBA>2.0.CO;2.
Botta SB, Ana PA, Zezell DM, et al. Adhesion after erbium, chromium:yttrium-scandium-gallium-garnet laser application at three different irradiation conditions. Lasers Med Sci 2009;24(1): 67–73. DOI: 10.1007/s10103-007-0521-3.
Quinto Jr J, Amaral MM, Francci CE, et al. Evaluation of Intra root canal Er,Cr:YSGG laser irradiation on prosthetic post adherence. J Prosthodont 2017; 1–5.
Hoshing UA, Patil S, Medha A, et al. Comparison of shear bond strength of composite resin to enamel surface with laser etching versus acid etching: An in vitro evaluation. J Conserv Dent 2014;17(4):320–324. DOI: 10.4103/0972-0707.136438.
International Standardization Organization. Dental materials – testing of adhesion to tooth structure. ISO/TS 11405. 2014; 1–17.
Zamataro CB, Ana PA, Benetti C, et al. Influence of Er,Cr:YSGG laser on CaF2-like products formation because of professional acidulated fluoride or to domestic dentifrice application. Microsc Res Tech 2013;76(7):704–713. DOI: 10.1002/jemt.22221.
Artun J, Bergland S. Clinical trials with crystal growth conditioning as an alternative to acid-etch enamel pretreatment. Am J Orthod 1984;85(4):333–340. DOI: 10.1016/0002-9416(84) 90190-8.
Ana PA, Velloso WF Jr, Zezell DM. Three-dimensional finite element thermal analysis of dental tissues irradiated with Er,Cr:YSGG laser. Rev Sci Instrum 2008;79(9):093910. DOI: 10.1063/1.2953526.
Benetti C, Ana PA, Bachmann L, et al. Mid-infrared spectroscopy analysis of the effects of erbium, chromium:yattrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation on bone mineral and organic components. Appl Spectrosc 2015;69(12):1496–1504. DOI: 10.1366/14-07726.
Reynolds IR. A review of direct orthodontic bonding. Br J Orthod 1975;2:171–180. DOI: 10.1080/0301228X.1975.11743666.
Leão Filho JC, Braz AK, de Souza TR, et al. Optical coherence tomography for debonding evaluation: an in-vitro qualitative study. Am J Orthod Dentofacial Orthop 2013;143(1):61–68. DOI: 10.1016/j.ajodo.2012.08.025.
Mahdian M, Salehi HS, Lurie AG, et al. Tissue characterization using optical coherence tomography and cone beam computed tomography: a comparative pilot study. Oral Surg Oral Med Oral Pathol Oral Radiol 2016;122(1):98–103. DOI: 10.1016/j.oooo.2016.03.021.
Chan KH, Tom H, Darling CL, et al. A method for monitoring enamel erosion using laser irradiated surfaces and optical coherence tomography. Lasers Surg Med 2014;46(9):672–678. DOI: 10.1002/lsm.22285.
Rajagopal R, Padmanabhan S, Gnanamani J. A comparison of shear bond strength and debonding characteristics of conventional, moisture-insensitive, and self-etching primers in vitro. Angle Orthod 2004;74(2):264–268. DOI: 10.1043/0003-3219(2004)074<0264:ACOSBS>2.0.CO;2.
Bishara SE, VonWald L, Lafoon JF, et al. Effect of a self-etch primer/adhesive on the shear bond strength of orthodontic brackets. Am J Orthod Dentofacial Orthop 2010;119(6):621–624. DOI: 10.1067/mod.2001.113269.