UV-Mediated Photofunctionalization of Indirect Restorative Materials Enhances Bonding to a Resin-Based Luting Agent
Abstract
Purpose. The potential of UV-mediated photofunctionalization to enhance the resin-based luting agent bonding performance to aged materials was investigated.
Methods. Sixty samples of each material were prepared.
Yttria-stabilized zirconia (YZr) and Pd-Au alloy (Pd-Au) plates were fabricated and sandblasted. Lithium disilicate glass-ceramic (LDS) was CAD-CAM prepared and ground with #800 SiC paper.
Half of the specimens were immersed in machine oil for 24 h to simulate the carbon adsorption. Then, all of the specimens (noncarbon- and carbon-adsorbed) were submitted to UV-mediated photofunctionalization with a 15 W UV-LED (265 nm, 300 mA, 7692 mu W/cm(2)) for 0 (control groups), 5, and 15 min and subjected to contact angle (theta) measurement and bonded using a resin cement (Panavia (TM) V5, Kuraray Noritake, Japan).
The tensile bond strength (TBS) test was performed after 24 h. The theta (degrees) and TBS (MPa) data were statistically analyzed using two-way ANOVA and Bonferroni correction tests (alpha=0.05).
Results. In the carbon-adsorbed groups, UV-mediated photofunctionalization for 5 min significantly decreased theta of all materials and increased TBS of YZr, and UV for 15 min significantly increased the TBS of LDS and Pd-Au.
In noncarbon-adsorbed groups, UV-photofunctionalization did not significantly change the theta or TBS except YZr specimens UV-photofunctionalized for 15 min. Conclusion.
UV-mediated photofunctionalization might have removed the adsorbed hydrocarbon molecules from the materials' surfaces and enhanced bond strengths of Panavia (TM) V5 to YZr, LDS, and Pd-Au. Additionally, UV-mediated photofunctionalization improved the overall TBS of YZr.
Further investigation on the optimum conditions of UV photofunctionalization on indirect restorative materials should be conducted.