Comparative evaluation of the shear bond strength of sixth and seventh generation bonding agents: an in vitro study

Aim: To compare the shear bond strength of sixth generation and eighth generation bonding agents to dentin. Materials and methods: Flat surface of dentin were exposed after reducing the enamel surfaces of forty human molar teeth and were divided into two groups(n=20), which were then bonded using Sixth-generation bonding agent, Prelude Dental Adhesive (Danville) and Seventh-generation bonding agent, Prelude One (Danville) which is a one bottle adhesive. Group I- Prelude Dental Adhesive system which is two bottle system (n=20) was applied as per manufacturer’s instructions. Group II - Prelude One which is a one bottle adhesive system (n=20) was also applied as per manufacturer’s instructions. Following this, composite cylinders were built up using a Teflon mould (3x2mm) on these prepared dentinal surfaces. Samples were stored in distilled water for 24 hours and tested for shear bond strength with universal testing machine. Shear force was applied perpendicular to the long axis of composite cylinder at adhesive-tooth interface until debonding occurred. The data obtained was tabulated and analyzed statistically using analysis of variance (ANOVA) test. Results: There was a significant difference in the shear bond strength of both the adhesives tested (P < 0.05). The seventh-generation adhesives showed significantly higher shear bond strength to dentin compared to sixth-generation adhesives. Conclusion: Among self-etch systems, single-step bonding agents are superior to two-step systems.