Bond Strength and Antimicrobial Activity of an OASys-Based Bonding Agent

Objectives: Previously, it was discovered that an Oxirane/Acrylate Interpenetrating Network System (OASys)-based bonding agent had antimicrobial properties in vitro. Objective: To further determine the in vitro antimicrobial properties and dentin bond strength to OASys composites of an OASys-based antimicrobial bonding system.
Methods: An experimental superhydrophobic OASys composite (OASys-UF, 25:30:15:30 weight ratio epoxidized hydrogenated bisphenol A (Epalloy 8370):dipentaerythritol penta/hexa acrylate (DPHA):urethane dimethacrylate:2-(Perfluorooctyl)ethyl acrylate was bonded to dentin using an unfilled OASys-based bonding resin (25:75 difunctional Epalloy 5001:DPHA) or Bisco ALL-BOND UNIVERSAL, and shear bond strength was determined. Control group consisted of a 70:30 BisGMA:triethyleneglycol dimethacrylate (TEGDMA) composite bonded to dentin using All-BOND. In vitro antimicrobial activity of the OASys-based bonding resin against C. albicans, S. mutans, A. viscosus, and S. sanguinis was also determined using a zone of inhibition test.
Results: The bond strength of All-BOND bonding the 70:30 BisGMA:TEGDMA control composite and the OASys-UF composite were 13.5±6.2 MPa and 11.7±3.9 MPa, respectively, demonstrating comparable bond strengths. The bond strength of the OASys bonding system to the OASys composite was 10.4±3.5 MPa. All failures were of a mixture of adhesive or mixed adhesive/cohesive type. OASys bonding resin demonstrated a zone of inhibition at 24 and 48 hours against C. albicans (20.0±1.0 mm and 20.3±0.6 mm, respectively), S. mutans (13.0±1.7 mm and 12.7.0±2.3 mm), A. viscosus (21.0±1.7 mm and 20.3±2.9 mm), and S. sanguinis (11.7±1.5 mm and 11.3±1.2 mm) when compared to BisGMA/TEGDMA (0.0±0.0 mm or no zone of inhibition), and positive (Peridex peroxide, ranging from 18.0±0.0 mm to 27.7±1.5 mm) and negative controls (PBS, no zone of inhibition) in vitro.
Conclusions: Adequate bond strengths were demonstrated for the OASys composite using All-BOND and the OASys bonding system. The OASys-based bonding resin also had significant antimicrobial effect in vitro.