2015 Volume 58 Issue 3 Pages 192-199
Purpose: In this study, the interaction between the acidic monomer MDP employed in Clearfil Tri-S Bond ND and enamel or dentin was examined in detail by comparing the changes in the carbon 13 nuclear magnetic resonance (13C NMR) spectrum obtained before and after reaction with enamel and dentin particles using a solid-state and liquid-state 13C NMR technique. The effect of the demineralization ratio of tooth apatite by acidic monomer MDP on the shear bond strength to enamel and dentin was examined.
Methods: Bovine crown enamel particles or bovine crown dentin particles of 0.400 g were suspended in 2.000 g of Clearfil Tri-S Bond ND, and the suspensions were vibrated for 10 minutes. After centrifuging these suspensions, liquid-state 13C NMR spectra of the supernatant solution of adhesives were observed using an EX-270 spectrometer. The ratio of intensity of the NMR peak of the vinyl methylene carbon for acidic monomer MDP employed in Clearfil Tri-S Bond ND to the NMR peak of that for HEMA detected in the 13C NMR spectrum was determined before and after reaction with enamel or dentin particles. The reduction in the peak intensity for MDP was determined by dividing the difference in the intensity ratio obtained before and after reaction by the intensity ratio obtained before reaction. The reduction was determined as the ratio of demineralization of tooth apatite by MDP. Furthermore, the bond strength of Clearfil Tri-S Bond ND to ground enamel and dentin was measured.
Results: When Clearfil Tri-S Bond ND interacted with enamel and dentin, the demineralization ratio of tooth apatite by acidic monomer MDP was 33.00% and 40.50%, respectively. In addition, the bond strength of Clearfil Tri-S Bond ND to the enamel showed a value of 15.04 MPa, and the bond strength to dentin showed a value of 17.39 MPa.
Conclusions: Based upon the foregoing, dentin showed a higher decalcification ratio of the tooth substance apatite ingredient of MDP combined with Clearfil Tri-S Bond ND than enamel. In addition, regarding the influence on bond strength, it significantly adhered to the dentin which showed a higher decalcification ratio of MDP than enamel.
