Comparative Evaluation of Shear Bond Strength of Flowable Composite Bonded to Teeth Enamel with Laser Surface Treatment

Abstract

Background: Acid etching of enamel appears to improve retention by selectively eroding certain hydroxyapatite formations and facilitating penetration by the development of resin tags. Aim of study: To evaluate shear bond strength (SBS) of flowable composite to non-lased and lased groups, compare the (SBS) of flowable composite between Total and Self-etch in non-lased and lased groups, and failure mode analysis.Materials and Methods: Forty bovine incisors were used, enamel surfaces was grounded by silicon carbide paper and samples were randomly assigned into two main groups (Group A: Non lased n=20, Group B: lased prepared n=20). Each main group was subdivided randomly according to the adhesive systems that used which are: total-etch adhesive and self-etch adhesive, which were applied to the prepared enamel surface according to manufacture instruction. Composite rod applied over the bonded area and cured. Samples were stored in distilled water at 370 for 24 hours. The evaluation of shear bond strength was employed by the use of universal testing machine. Results: The results of Student’s t-test showed that there was no significant difference between the lased and non-lased enamel groups (P= 0.311). One–way ANOVA test and Duncan's Multiple Range test that compare shear bond strength between total and self-etch adhesives showed no significant difference in both lased and non-lased enamel groups. Conclusion: The mean shear bond strength and enamel surface etching obtained with an Er,Cr:YSGG laser was not comparable to that obtained with nonlased enamel surface.