Adhesive Property of a New Self-etching Bond System “MTB-200”

Kuraray Medical Inc. has developed a new self-etching bond system "MTB-200". "MTB-200" is a single-component and light-cured single-step fluoride-releasing bonding system comprised of an adhesive phosphate monomer (MDP), methacrylate monomers, water, ethanol, initiators, sodium fluoride and filler. It contains a new photo-initiator for enhanced curing characteristic and a new hydrophobic methacrylate for reduced water absorption. Objectives: The purpose of this study was to compare the micro-tensile bond strength (µTBS) of "MTB-200" to human dentin with other 5 commercial single-step adhesives; CLEARFIL S³BOND/ Kuraray Medical, OptiBond All-In-One/ Kerr, Adper Easy Bond/ 3M ESPE, G-BOND PLUS/ GC and BOND FORCE/ Tokuyama. Methods: Crowns of extracted human molars were removed using a low-speed cutting device to create flat dentin surfaces. Surfaces were finished with 600-grit SiC paper and adhesives were applied according to the manufacturer's instructions. CLEARFIL AP-X (Kuraray Medical) was used for composite build-up to a thickness of 4mm. After storage in 37˚C water for 24 hrs, the specimens were cut in two perpendicular directions to obtain sticks with approx. area of 1.0mm². Sticks of each group were further divided into two groups, and half of the sticks were subjected to thremocycling (4˚C-60˚C, 1 min. each, 4,000 cycles: TC4000). The µTBS was measured using a universal testing instrument (Shimadzu). Results: The µTBS after 24 hrs immersion and TC4000 are shown in Table 1. "MTB-200" showed the highest bond strengths to human dentin both after 24hrs and TC4000 among the single-step adhesives tested in this study.

Table 1                                                                                                                                   MPa(SD)

Conclusions: This result indicated that the µTBS of "MTB-200" might exhibits reliable clinical performance equal or superior to single-step adhesives used in this study.