Shear Bond Strength of Self-Adhesive and Self-Etching Resin Cements to Dentin for Indirect Restorations

This study assessed and compared the shear bond strength of self-adhesive and self-etching resin cements for indirect aesthetic restorations to dentin. Four different materials, lithium disilicate ceramics, zirconia ceramics, polymethyl methacrylate (PMMA) composites, and hybrid materials, were used for indirect restorations cemented to dentin. The null hypothesis was that there would be no differences in shear bond strength between the investigated materials. Eighty extracted human molars were used. Eighty dentin specimens with a flat surface were prepared and randomly distributed in groups of 10 (n = 10). From each material (Cerasmart 270, Initial LiSi Blok, Katana ZR Noritake, and Crowntec Next Dent), 20 blocks were made and cemented to the dentin samples. Half of the blocks from each material were cemented to dentin using self-etching resin cement (Panavia V5), and the other half using self-adhesive resin cement (i-CEM). After the specimens were prepared, a laboratory test was conducted to evaluate the shear bond strength. The fracture type was determined using a light microscope, and SEM confirmed the results. The results were statistically analysed. All materials cemented with self-etching cements (Panavia V5) showed statistically higher shear strength values than those cemented with self-adhesive resin cement (i-CEM). In the specimen groups where self-adhesive cement (i-CEM) was used, Cerasmart 270 bonded statistically better. A statistical difference was found between all groups of materials cemented with self-etching cement. The Initial LiSi Block showed the strongest bond, followed by Katana Zr Noritake, Crowntec NextDent, and Cerasmart 270. Adhesion fracture to dentin was observed for all groups cemented with i-CEM. This study highlights the superior performance of self-etching cements in terms of shear bond strength. 10-Methacryloyloxydecyl dihydrogen phosphate (10-MDP), a functional monomer, was found to enhance adhesion strength significantly. However, using self-adhesive cements was associated with a weaker bond to dentin, highlighting the importance of the right cementing agent in restorative dentistry.