Adhesives' µTBS compared to µ-tensile cohesive strength of adjacent specimens

Introduction: Bonded restorations should ideally produce interfaces with µTBS comparable to µ tensile cohesive strength, µTCS, of the dentin or enamel being replaced. Objective: to compare µTBS of interfaces, produced with different adhesives, to µTCS of dentin adjacent to tested specimens. Materials & methods: Surgically extracted human third molars were stored in distilled H₂O for less than a month until usage. They were randomly assigned to one of nine groups ( Adper Prompt L-Pop (PLP), Xeno V (XV), Adhese One (AON), Adper ScotchBond SE (SBSE), Optibond All in One (OPT), Clearfil S3 Bond (CS3), Clearfil SE Bond (CSE), Clearfil DC (DCB), Adhese (ADH)). Roots and oclusal enamel were removed, each fragment glued to a methyl-methacrylate cubical piece, and perfused (20 cm distilled H₂O) through all bonding procedures. Two parallel furrows (2mm wide, 2mm depth, 2 mm separation) were drilled in oclusal dentin and filled (adhesive to be tested + Filtek Z250). A crown (2mm height) was built up. Restored samples were sectioned producing 1,5 x 1,5 mm dentin-resin specimens from furrows and from adjacent zones. All were rounded to induce fracture at a similar relative depth i.e.: at interface in those obtained from furrows (to test µTBS), and at an equivalent level in those obtained from adjacent areas (to test µTCS). Rounded specimens were submitted to tension until detachment. Results:  differences between µTCS and µTBS were not statistically significant for PLP, AON, CSE, OPT, CDC, ADH. Conclusions: some adhesives were able to produce a bonded interface with similar mechanical characteristics to dentin. Acknowledgements: Materials were gently provided by manufacturers. In partial fulfillment or requirements of PhD (J Bascones)