Effect of Ultraviolet Irradiation on Tensile Bond Strength of Resin Composites and Multi-Purpose Bonding System Treated Adherends

<p>Various types of multi-purpose adhesion system with easy manipulation, in which universal surface treatment is possible by systematically combining treatment materials that can bind to adherends, such as metals, ceramics, and resin composite, have been commercialized and clinically used.</p><p>However, because their compositions are comparatively complicated, there are many unclear points. Therefore, in this study, regarding the various types of multi-purpose adhesion system, to precisely investigate the relationship between differ ences in adherends and the effectiveness of adhesion to resin composite, we performed a tensile bond strength test and evalu ated the characteristics of failure mode after the test. Furthermore, to investigate the improvement of the bond strength of resin composite due to ultraviolet irradiation to each adherend, we also evaluated the contact angle of distilled water on each adherend surface, and the tensile bond strength of the multi-purpose adhesion system, using a low-pressure mercury lamp to irradiate with ultraviolet light at wavelengths of 185 and 254 nm, and an excimer lamp to irradiate with ultraviolet light at a single wavelength of 172 nm.</p><p>As a result, for adherends (12%Au-Ag-Pd alloy, Clearfil AP-X, CEREC Blocs, and Nano-Zirconia) after sand-blast treat ment, various types of multi-purpose adhesion system showed bond strengths equal to or greater than those of the conven tional surface treatment materials applied to each different adherend. In particular, regarding three types of adherend (12%Au-Ag-Pd alloy, Clearfil AP-X, and CEREC Blocs), a multi-purpose adhesion system (UNIVERSAL PRIMER) showed a significantly greater adhesive strength, in comparison with the two other types of multi-purpose adhesion system and conven tional application methods in which the surface treatment material is applied to each different adherend. The contact angle of distilled water on every adherend decreased after ultraviolet irradiation, and the hydrophilicity more markedly increased us ing the excimer lamp with stronger light energy. Furthermore, in the evaluation of the improvement of bond strength by changing the adherend surface to being more hydrophilic using the UNIVERSAL PRIMER, the bond strength was similar to that of the specimen without ultraviolet treatment, showing no significant differences. However, in the Weibull analysis of the reliability of the bond strength, the dispersion of the bond strength decreased with 12%Au-Ag-Pd alloy, Clearfil AP-X, and Nano-Zirconia, excluding CEREC Blocs; therefore, decreases in the bond strength could be prevented by ultraviolet treatment.</p>