Early bond strengths of 4-META/MMA-TBB resin cements to CAD/CAM resin composite.

The purpose of this study was to evaluate the early tensile bond strengths of three different resin cements; Super Bond C&B (conventional and quick type) and ResiCem to a CAD/CAM composite block. A CAD/CAM composite block (Shofu Block HC) was ground and silanized according to the manufacturers' instructions before cementation. A conventional tensile bond strength test (Ø: 4 mm) was performed 10 min, 1 h and 24 h after bonding. Super Bond C&B (quick type) showed the highest bond strength at 24 h. However, results of a three-point bend test showed the mechanical properties were weaker for the Super Bond C&B cements compared with composite cement, Resicem. The 4-META/MMA-TBB resin is a suitable resin cement to bond to a CAD/CAM composite block.

Dentin bonding performance and interface observation of an MMA-based restorative material.

The purpose of this study was to evaluate bonding performance and dentin interface acid resistance using a 4-META/MMA-TBB based restorative material (BF) compared to a conventional 4-META/MMA-TBB resin cement (SB), and the effect of sodium fluoride (NaF) addition to the materials. Dentin surfaces were treated with 10% citric acid-3% ferric chloride (10-3) or 4-META containing self-etching primer (TP), followed by application of BF or SB polymer powders with or without NaF, to evaluate microtensile bond strength (µTBS) in six experimental groups; 10-3/SB, 10-3/BF, TP/SB, TP/BF, TP/SB/NaF and TP/BF/NaF. SEM observation of the resin-dentin interface was performed after acid-base challenge to evaluate interfacial dentin resistance to acid attack. TP/BF showed highest µTBS, while NaF polymers decreased µTBS. TP/BF showed funnel-shaped erosion at the interface, however, NaF polymers improved acid resistance of interface. In conclusion, BF demonstrated high µTBSs and low acid-resistance at the interface. NaF addition enhanced acid resistance but decreased µTBS.