ASSESSMENT OF THE EFFECT OF ER:YAG LASER CONDITIONING ON BOND STRENGTH OF FISSURE SEALANTS

Abstract

The purpose of this study was to evaluate the effect of Er:YAG laser enamel etching and/or phosphoric acid enamel etching on shear bond strengths (SBS) of fissure sealants. 42 extracted non-carious third molars, washed and cleaned with a fluoridefree pumice, were sectioned in the cement-enamel junction. Coronal section were embedded in resin and labial surfaces of crowns were flattened for an enamel surface area of 3mm in diameter. The specimens were randomly assigned to six groups of 7 teeth each. Group 1:Acid etching+Clinpro(3M ESPE, USA), Group 2:Er:YAG laser etching (Fidelis Plus II, Fotona)+Clinpro, Group 3:Laser etching+acid etching+Clinpro, Group 4:acid etching+FissuritF(Voco,). Group5:Laser etching+FissuritF, Group 6:Laser etching+acid etching+FissuritF. Samples were etched with 37 % phosphoric acid gel for 20 sec. and/or Er:YAG laser (10 Hz, 120 mJ). Cylindrical molds (D:3mm, H:2mm) were placed on substrate surfaces; and sealants were applied and cylinders of fissure sealants were submitted to SBS test in an Instron machine. SBS data in MPa was statistically analyzed by Tukey Multiple Comparisons test. Mean+ SD values (MPa): Group 1: 14.52 +/- 2.33, Group 2: 5.43 +/- 2.02, Group 3: 9.14 +/- 3,08, Group 4: 9.39 +/- 2.94, Group 5: 5.03 +/- 2.68, Group 6: 8.31 +/- 2.41. Significant differences were determined between Gr 1- Gr 2 (p<0.001), Gr 1- Gr 3 (p<0.01), Gr 1- Gr 4 (p<0.01), Gr 1- Gr 5 (p<0.001), Gr 1- Gr 6 (p<0.01) and Gr 4- Gr 5 (p<0.05). No significant differences were found between the other groups. Laser enamel etching, laser+ acid enamel etching have demonstrated lower SBS values for the fissure sealants tested than enamel acid etching.