Comparative Evaluation of the Effect of Laser Etching on the Shear Bond Strength of Crowns Cemented with Two Different Luting Agents: An In Vitro Study

Purpose: The aim of this study was to compare the shear bond strength of crowns cemented on natural teeth after surface treatment of the enamel with an erbium-doped yttrium aluminum garnet (Er:YAG) laser. Materials and Methods: Crown preparation was done for 40 full-metal crowns, and wax patterns with loops were cast in a cobalt-chromium alloy. The Er:YAG laser was used for surface treatment of some teeth, and teeth without surface treatment acted as the control. Glass-ionomer and self-adhesive resin luting cements were used for cementation. Shear bond strength was tested using a universal testing machine, and statistical analysis was done using paired t test. Scanning electron microscopy analysis was also carried out to study alterations of the enamel and dentin surfaces. Results: Significant increase in shear strength was noted after laser etching the teeth with Er:YAG laser for both types of cement (P .0001). Conclusion: The results showed that surface treatment using an Er:YAG laser resulted in significant increase in retention of crowns.