24 hours and 3-months bond strength between dual-cured resin cements and simplified adhesive systems.

This study evaluated the bonding compatibility between dual-cured resin cements and simplified adhesive systems (one-step self-etch and two-step etch & rinse), measured after 24 hours and 3 months. The occlusal dentin surfaces of 24 human third molars were exposed and flattened. Teeth were randomly assigned to 3 groups and treated with different combinations of adhesive system and resin cement [G1-Single Bond/Rely X ARC (SB/RX); G2-Excite DSC/Variolink II (EX/VR); G3-Adper Prompt/Rely X ARC (AD/RX)]. Indirect composite restorations were cemented on flattened surfaces, and sectioned to obtain multiple bonded beams for the microtensile bond strength test. The beams from each tooth were tested under tension after 24 hours and 3 months (ANOVA/ Tukey's test, alpha=5%). Failure patterns were evaluated with scanning electron microscopy. After 24h, AD/RX presented the lowest bond strength mean values. AD/RX specimens did not withstand three months storage. SB/RX and EX/VR presented similar bond strengths in both periods tested. The association AD/RX resulted in low bond strength mean values, especially after storage. Cementing indirect restorations using one-step self-etch adhesive systems and dual-cured resin cements would be clinically unreliable.