Micro-Raman Vibrational Identification of 10-MDP Bond to Zirconia and Shear Bond Strength Analysis

Abstract

So far, there is no report regarding the micro-Raman vibrational fingerprint of the bonds between 10-methacryloyloxy-decyl dihydrogen phosphate (10-MDP) and zirconia ceramics. Thus, the aim of this study was to identify the Raman vibrational peaks related to the bonds of 10-MDP with zirconia, as well as the influence on microshear bond strength. Micro-Raman spectroscopy was employed to assess the vibrational peak of 10-MDP binding to zirconia. Microshear bond strength of the dual-cure resin cement to zirconia with the presence of 10-MDP in composition of experimental ceramic primer and self-adhesive resin cement was also surveyed. Statistical analysis was performed by one-way ANOVA and Tukey's test (p < 0.05). Peaks at 1545 cm^-1 and 1562 cm^-1 were found to refer to zirconia binding with 10-MDP. The presence of 10-MDP in both experimental ceramic primer and self-adhesive resin cement improved microshear bond strength to zirconia ceramic. It can be concluded that the nondestructive method of micro-Raman spectroscopy was able to characterize chemical bonds of 10-MDP with zirconia, which improves the bond strengths of resin cement.

Figure 1

Mean and standard deviation of μSBS (MPa) of dual-cure resin cement after ceramic primers (CP: Clearfil Ceramic Primer; EP: an experimental primer; NP: no primer) applied on Y-TZP ceramics. Different capital letters indicate statistical difference (p < 0.05).

Figure 2

Results of μ-SBS test (MPa) of self-adhesive resin cements bonded to Y-TZP ceramics. (CCP: RelyX U200; ECP: experimental self-adhesive dual-cure resin cement with MDP; and ECN: experimental self-adhesive dual-cure resin cement without MDP). Different capital letters indicate significant difference (p < 0.05).

Figure 3

Micro-Raman spectra of Y-TZP ceramic (Y-TZP), primers-treated ceramics (Y-TZP + CP and Y-TZP + EP), commercial primer (CP), experimental primer (EP), and neat 10-MDP (10-MDP). Peaks at 1636 cm⁻¹ and 1803 cm⁻¹ refer to Zr-O bonds; peak at 1630cm⁻¹ is relative to C=C bonds and 1710 cm⁻¹ to C=O bonds of 10-MDP. Asterisks (∗) are indicating 1545 cm⁻¹ and 1562 cm⁻¹ peaks which only appeared after application of 10-MDP containing primers on Y-TZP ceramics.