Shear Bond Strength of Self-Etching Adhesive Systems to Er:YAG Laser-Prepared Dentine with and without Pulpal Pressure Simulation

Objective: This study was conducted to study the role of pulpal pressure on the shear bond strength of composite resin bonded to Er:YAG laser-prepared or bur-prepared dentine surfaces using a self-etching adhesive system. Materials and Methods: The occlusal surfaces of 80 human third molars were ground flat to expose the dentine. The dentine was prepared using either a carbide bur or an Er: YAG laser at 350 mJ/pulse and 10 Hz (fluence 44.5 J/cm(2)). Clearfil SE Bond was then applied with or without pressure. Rods of composite resin were bonded to dentine surfaces and shear bond tests were carried out. Results: When the Clearfil SE Bond was used without pressure, the difference between the shear bond strength values of bur-prepared and laser-prepared dentine surfaces was significant. When the Clearfil SE Bond was used with pressure, the difference of shear bond strength values was not significant between the two types of surface preparation. Conclusion: The absence of smear layer formation during the preparation of the dentine by the Er: YAG laser did not improve the adhesion values of self-etching adhesive systems.