Effect of self-etching ceramic primer on bond strength of zirconia-reinforced lithium silicate ceramics

This study evaluated the effect of self-etching ceramic primer (SECP) on shear bond strength (SBS) of zirconia-reinforced lithium silicate (ZLS) ceramics. Two hundred and seventy block-specimens of two types of ZLS ceramics and one type of lithium disilicate (LS) ceramics were prepared. Ninety blocks of each material were divided into three groups (n = 30), namely group 1: no surface treatment (control), group 2: hydrofluoric acid (HF), silane-based primer (S), and group 3: SECP. Resin cement was applied, and light-cured for build-up. Shear bond strength (SBS) test was used. Half of the bonded specimens (n = 15) were tested after storage in distilled water for 24 h, whereas the other half were tested after 5000 thermo-cycles. The failure modes were evaluated using scanning electron microscope (SEM). The SBS values for samples treated with SECP and HF + S within the respective materials were statistically comparable (p > 0.05). Thermocycling significantly reduced the SBS (p < 0.05) for all ceramic materials in groups 2 and 3. Mixed failure followed by adhesive failure were the most common failure modes in groups 2 and 3, whereas pretest failure was only detected in group 1. Considering the limitations of the study, with respect to in vitro bond strength, the SECP is an alternative for the conditioning of internal surface of glass ceramics.