Evaluating the Effect of ER,CR.YSGG Laser and Phosphoric Acid Etching on Shear Bond Strength of Composite on Enamel of Primary Teeth(in Vitro Study)

Introduction: Enamel surface etching improves the bonding of the composite resin material. Acid etching is the conventional method. Recently, erbium lasers have been used for this purpose. Objectives: This study is to compare the shear bond strength of composite resin bonded to enamel of primary teeth after etching using Erbium chromium –YSGG laser and phosphoric acid etching. Methodology: An Experimental in vitro study was conducted on thirty extracted or exfoliated primary molars that were divided into three groups. Group I Er,Cr:YSGG Laser etching with power set at 1W, Group II Er,Cr:YSGG laser with power set at 1.5W and group III acid etching using phosphoric acid. Specimens were assigned for shear bond strength (SBS) evaluation test. Only six specimens were evaluated qualitatively to asses enamel surface topography using scanning electron microscopy. Results: SBS of acid etching group showed the highest followed by 1.5W laser-etching group, while 1W laser etching group demonstrated the least mean shear bond strength. The acid etched enamel was statistically significantly higher (P < <0.0001) than that other groups. Conclusions: The mean SBS of composite with acid etching is significantly higher in comparison to Er, Cr: YSGG (operated at 1W & 1.5W for 10 s) laser etched enamel. Keywords: Primary teeth, Erbium chromium: YSGG, Laser etching. Running title: Effect of Er,Cr.