Daniela S Lopes1, Daisa L Pereira2, Claudia Cbo Mota3, Luciana Sa Melo4, Patricia A Ana5, Denise M Zezell6, Anderson Sl Gomes7. 1. Department of Prosthesis and Oral and Facial Surgery, School of Dentistry, Federal University of Pernambuco (UFPE), Recife-PE, Brazil. 2. Department of Physics, University of Sao Paulo and Center for Lasers and Applications, Nuclear and Energy Research Institute (IPEN-CNEN/SP), Sao Paulo-SP, Brazil. 3. Department of Dentistry, School of Dentistry, Caruaruense Association of Technical and Higher Education (ASCES), Caruaru-PE, Brazil. 4. Department of Physics, Federal University of Pernambuco (UFPE), Recife-PE, Brazil. 5. Department of Biomedical Engineering, Federal University of ABC (UFABC), Sao Bernardo do Campo-SP, Brazil. 6. Department of Physics, Center for Lasers and Applications, Nuclear and Energy Research Institute (IPEN-CNEN/SP), Sao Paulo-SP, Brazil. 7. Department of Physics, School of Dentistry, Federal University of Pernambuco (UFPE), Recife-PE, Brazil, Phone: +55 8121268000, e-mail: anderson@df.ufpe.br.
Abstract
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.
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.
Entities:
Keywords:
Cr:YSGG laser; Enamel conditioning; Er; Laboratory research Orthodontic brackets.