Effect of Erbium Laser on Microtensile Bond Strength of Fissure Sealant in Primary Teeth: An in vitro Study

Background: Laser etching has several advantages as compared with conventional acid etching. However, results of earlier studies on conditioning surfaces with erbium, chromium:yttrium–scandium–gallium–garnet (Er, Cr:YSGG) before application of the fissure sealant have been inconclusive. Aim: The study aimed to evaluate the microtensile strength of resin-based fissure sealant bonded to primary enamel conditioned by Er, Cr:YSGG laser with varying power outputs. Materials and Methods: Fifty sound primary first molars were randomized into the following five groups based on pretreatment choice: Group 1: 3.5 W laser etching + acid etching; Group 2: 2.5 W laser etching + acid etching; Group 3: 3.5 W laser etching with no acid; Group 4: 2.5 W laser etching with no acid and Group 5: acid etching with no laser. Acid etch was performed with 35% orthophosphoric acid for 30 s. Laser etching was performed with Er, Cr:YSGG (2780 nm) laser using G6 tips and 600 μm diameter, 2.5 W or 3.5 W power outputs, pulse duration of 140 μs and a repetition rate of 20 Hz. Sealant was applied on the buccal surface followed by an incremental buildup with composite resin. Microtensile bond strength was assessed and compared among the five groups using one- and two-way ANOVA. Results: There was no statistical difference in the mean bond strength between groups except in Group 4 (9.66 MPa) (Group 1: 15.57 MPa; Group 2: 14.18 MPa; Group 3: 14.78 MPa; Group 5: 14.63 MPa). Conclusion: Pretreatment with 3.5 W Er, Cr:YSGG laser alone results in microtensile bond strengths similar to that produced by acid etching, indicating that enamel etching using 3.5 W Er, Cr:YSGG laser would result in the long-term success of pit and fissure sealants in primary teeth.