Assessment Of Shear Bond Strength And Failure Modes Between The Base And Bulk Resin Restorative Materials; An In Vitro Comparative Study

Afreen Bilgrami, Fazal-ur-Rehman Qazi, Kausar Ali Syed, Omair Anjum, Malik Saleem, Bakhtawar Farooq

Abstract

Objective: To assess the comparative shear bond strength and failure modes between the base and bulk Resin restorative materials.
Place of Study: Dental Materials Testing Laboratory, Dr. Ishrat-ul-Ibad Khan Institute of Oral Health Sciences, Karachi.
Study Design: In Vitro, Experimental Study
Duration of Study: One week (August 2021)
Methodology: This experimental material research was conducted at the Dental Materials Test site, Dr. Ishrat-ul-Ibad Khan Institute of Oral Health Sciences, Karachi. Using convenient sampling a total of 16 samples were prepared, eight had Z350 (Material A) while the other eight used Ceram X (Material B) as bulk restorative material sandwiched with GIC as the base material. Samples were made using two sheets of polytetrafluoroethylene mold. Every single sheet contained holes that were 4×2 mm (diameter X thickness). Firstly, these samples were placed in distilled water and later for complete polymerization in the incubator. After this, they were thermo cycled and ultimately checked for shear bond strength.
Results: Material A presented the mean value of 148.522±113.928 with single mixed and all other adhesive failure modes, whereas, Material B showed single cohesive failure and the rest of the adhesive failures with a mean of 6062,76±2547,18. Conclusion: Sufficient bonging strengths were observed between the base and bulk resin restorative materials using the sandwich technique, however, Nano-composite “Ceram X” has demonstrated slightly better shear bond strength in comparison to Z350. In addition, adhesive failure in both groups clearly indicated the lack of an adhesive system in between the sandwich material.