Objective : The objective of this study was to evaluate the effect of various surface treatments to a zirconia framework material on bond strength of a direct composite material.
Materials and Methods : A direct composite material (Clearfil Majesty) was bonded to the zirconia disks treated with the following primers (n = 11) : Clearfil Ceramic Primer (CCP), Clearfil Photo Bond (CPB), Estenia Opaque Primer (EOP), MR Bond (MRB), Porcelain Liner M (PLM), Porcelain Liner M Liquid B (PLB), Universal Primer (UNP), or no priming (CON). The shear bond strength was tested after 24 hours' water storage. Data were analyzed with the Steel-Dwass U test (p = 0.05).
Results : The CPB group showed the significantly highest bond strengths. The CCP and EOP groups had significantly higher bond strength values than the CON, MRB, PLB, PLM, and UNP groups, whereas the CON group revealed the lowest bond strengths.
Conclusion : Combined application of a hydrophobic phosphate monomer (MDP) and polymerization initiators enhanced the bond strength of a direct composite material to a zirconia framework material.