Effect of Different Nd:YAG Laser Power Outputs on Bond Strength of Resin Cement to Zirconia in Comparison to Sandblasting

[摘要] Introduction: This study investigated the effect of various laser powers on the shear bond strength(SBS) of resin cement to the zirconia surface.Methods: Seventy-five zirconia disks were prepared and assigned to five groups including no surfacetreatment (control group), sandblasting with 50 µ Al2O3 particles (second group), and Nd:YAG lasertreatments with 2 W, 2.5 W and 3 W powers respectively (third, fourth and fifth groups). Afterwards,composite resin cylinders were cemented on zirconia disks using dual-curing resin cement. Beforethermocycling (2000 cycles, 5-55°C), all samples were placed in distilled water at 37°C for 24 hours.Using a universal testing machine at the crosshead speed of 0.5 mm/min, the SBS was examined.Also, using a stereomicroscope, the failure type was determined. Data analyses were performedusing Welch and Games-Howell tests (P< 0.05).Results: The mean bond strength difference between the control group and the other groupswas significant. The respective bond strength from the highest to the lowest was observed inthe sandblast group, the laser group with 2.5 W power, the laser group with 3 W power, thelaser group with 2 W power, and finally the control group. However, no significant differencewas observed between different laser groups (P< 0.05). Also, there was no significantdifference between the sandblast and laser groups with 2.5 W and 3 W power (P< 0.05).Most of the failures in the sandblasting and laser groups with powers of 2.5 W and 3 W weremixed, but in the control and 2 W laser groups, most of the failures were of adhesive nature.Conclusion: The highest bond strength was achieved by sandblasting with Al2O3 particles and thenusing an Nd: YAG laser with a power of 2.5 W.

[学科分类] 基础医学

[关键词] Zirconia ceramic;Air abrasion;Nd: YAG laser;Shear bond strength