Comparative Evaluation of the Bonding Efficacy of Multimode Adhesive, Two-Step Self-Etch Adhesive, and a Total-Etch System to Pulpal Floor Dentin - An In vitro Study.

Background: Postendodontic restoration with composite resins has gained popularity due to the development of more reliable adhesives with simplified bonding procedures and less technique sensitivity. Pulpal floor dentin is a complex biological structure and a more challenging bonding substrate. Hence, appropriate selection of the bonding agent for these regions of the tooth is important.

Aims: To compare the shear bond strength of a new generation of dental adhesives referred to as multimode adhesives, two-step self-etch adhesive, and a total-etch system to pulpal floor dentin.

Materials and methods: Sixty human mandibular molars were sectioned with a slow speed diamond disc to expose the pulp chamber and divided into four groups of 15 teeth each, based on the bonding agent used. Group A: Single bond universal (self-etch); Group B: Single Bond Universal (etch-and-rinse), Group C: Clearfil SE Bond, Group D: Adper Single Bond 2. Using a split Teflon mold, composite cylinders were built on the prepared dentinal surfaces. The shear bond strength was then evaluated with the universal testing machine.

Results: Two step self-etch adhesives recorded higher shear bond strength than total-etch and multimode/universal adhesives applied in both self-etch and etch-and-rinse techniques.

Conclusion: The self-etching/priming system bonded more strongly to the pulpal floor dentin than multimode adhesive and total-etch system.