Bond Strength of Thermally Aged CAD/CAM Hybrid Nanoceramic Repaired with Nanohybrid Resin Composite

Abstract

Purpose. To assess shear bond strength (SBS) of nanohybrid resin composite used to repair CAD/CAM Hybrid Nanoceramic ceramic after various surface treatments. Materials and Methods. SHOFU HC Hybrid Ceramic disks were sliced to obtain circular-shaped specimens (n= 30). All specimens were thermocycled (5000 thermal cycles), then divided into three groups according to surface treatment performed (sandblasting, HF acid etching, and laser irradiation) (n = 10). Repair with nanohybrid resin composite was performed. SBS values were obtained, and failure modes were determined. Data were statistically analyzed (P ≤ 0.05). Results. The highest SBS mean value was found with (Sandblasting), while the lowest mean value was found with (Laser). There was a statistically significant difference between (Sandblasting), (Hydrofluoric acid) and (Laser) groups where (p=0.001). Statistically significant difference was found between (Sandblasting) and each of (Hydrofluoric acid) and (Laser) groups where (p=0.003) and (p=0.001) respectively, while no statistically significant difference was found between (Hydrofluoric acid) and (Laser) groups where (p=0.291). Conclusion. Surface treatment of the CAD/CAM hybrid nanoceramic material surface with sandblasting before repairing is mandatory to enhance the bond strength with nanohybrid resin composite repairing material. HF acid etching and laser irradiation are alternative surface treatment methods for CAD/CAM hybrid nanoceramic materials.