Resistance of composite and amalgam core foundations retained with and without pins and bonding agents.

To compare the resistance of different amalgam and composite core foundations retained by pins, bonding agents, or both, 100 molars were mounted in acrylic resin and their occlusal surfaces were reduced to expose dentin. Pins were inserted at the four line angles of the teeth and matrices were placed. Bonding agents were applied according to the manufacturers' instructions. Amalgam was handcondensed and composite was incrementally added and photocured. Restorations were adjusted to produce specimens (n = 10) 5 mm in height with a 1 mm bevel at the axial-occlusal surface. After immersion in deionized water for 24 hours, specimens were loaded at a 45 degree angle on their beveled surfaces in a Universal Testing Machine at a crosshead speed of 0.02 in./minute. ANOVA and Tukey's tests indicated that FluoroCore 2 (with or without pins) was statistically stronger than all other combinations (p < 0.05).

An evaluation of dentin conditioners for resin-modified glass ionomer cements.

This study sought to test the null hypothesis that there was no difference between three dentin conditioners in terms of how they affected the shear bond strength to dentin of three resin-modified glass ionomer (RMGI) cements. One hundred twenty caries-free third molars were mounted in acrylic resin and their occlusal surfaces were reduced to within 2 mm of their cemento-enamel junction (CEJ). Of the three cements tested, Rely-X Plus (22.7 MPa) and Fuji CEM (19.0 MPa) produced the highest bond strengths when dentin was treated with 37% phosphoric acid and followed by the application of Optibond Solo Plus and BondLink. Among the dentin conditioners tested, Fuji Plus Conditioner increased bond strengths for all three cements more than leaving the smear layer intact, although the increase was not statistically significant. Dentin treated with Cavity Conditioner demonstrated the weakest bond strengths.