The Effect of the Water Flow Rate During Laser Irradiation on the Bond Strength of Glass Fiber Posts

Objective: This study aimed to investigate the effect of the water flow rate during laser irradiation on the bond strength of GFRC posts. Background: Due to the ablation mechanism, water molecules must be present in the target tissue for effective results with erbium lasers. Materials and methods: Sixty glass fiber posts were divided into six equal groups: control groups, sandblasting with 30 μm Al2O3 particles, 9.5% hydrofluoric acid (HF), and three different flow rates (1%, 50%, and 100%) laser groups (n = 10). Resin cement was applied to the surfaces of the fiber posts. Then, 1 mm thick sections were taken from each specimen and micro tensile bond strength test was applied. The data obtained were statistically analyzed by a one-way analysis of variance and Tukey’s HSD test. Results: According to the statistical analysis results, there was a significant difference between the bond strength values of all the groups (P < 0.001). The highest bonding value was obtained in the sandblasted group (12.25 ± 0.38) and the lowest in the control group (5.64 ± 0.6). After sandblasting, the highest value was observed in the laser applied group (10.57 ± 0.64) at 100% flow rate. Conclusions: As the water flow rate decreases in laser applications, the bond strength between the fiber post and resin cement decreases.