Effect of different surface treatment protocols on the shear bond strength of perforation repair materials to resin composite

Abstract

The adhesion between the resin composite and perforation repair materials critically influences the treatment outcomes. This study aimed to investigate the effect of different surface treatment on the bond strength between the perforation repair materials and resin composite. Ninety blocks were prepared from Mineral trioxide aggregate (MTA) Angelus, EndoSequence (ERRM) and one experimental Nano-MTA (n = 30 each). Then, they were divided into two subgroups according to the surface treatment performed, which was either etching with phosphoric acid gel or air abrasion with Al2O3 particles. Adhesive system and resin composite were applied according to the manufacturers’ instructions. Specimens were tested for shear bond strength (SBS) tests using a universal testing machine. Failure modes were evaluated under a stereomicroscope. Data were analyzed using two-way ANOVA and Tukey’s test. Perforation repair materials had a significant effect on SBS at p = 0.0008, while the surface treatment showed an insignificant effect on the SBS at p = 0.0612. After both surface treatment techniques; ERRM revealed the highest SBS mean values followed by MTA Angelus then Nano-MTA. There was no statistically significant difference between each of ERRM and MTA Angelus, and between MTA Angelus and Nano-MTA. Cohesive and mixed modes of failures were the most predominant failure modes in all groups. ERRM had the best bonding to resin composite. Both tested surface treatments performed similarly with ERRM and the experimental Nano-MTA regarding SBS to resin composite. Air abrasion surface treatment was considered more successful with MTA Angelus compared to phosphoric acid regarding SBS to resin composite. Abbreviation: MTA: Mineral trioxide aggregate; ERRM: EndoSequenceBC RRM-Fast Set Putty; SBS: shear bond strength; Nano-WMTA: Nano-white mineral trioxide aggregate; TEM: Transmission electron microscope