Effects of Various Functional Monomers on Adhesion Between Immediate Dentin Sealing and Resin Cement

Acidic functional monomers are crucial components in self-etch adhesive systems, with the most popular being phosphate and carboxylic methacrylates. When self-etch adhesive systems are selected as immediate dentin sealing (IDS) for an indirect restoration, they will be in direct contact with the adhesive system of the resin cement on the restoration. The purpose of this study was to compare relative bond strength produced by different combinations of IDS and adhesive system monomers in order to identify the most effective bond. Premolar teeth were divided into 13 experimental groups (n=10), each representing a particular combination of IDS monomer and resin cement monomer. The upper half of each crown was cut off horizontally to expose the dentin as a flat surface. The IDS assigned for each group was applied to the dentin and polymerized. Previously polymerized and sandblasted resin composite rods representing a restoration were bonded to the IDS using the resin cement assigned for that group, then tested for shear bond strength and analyzed with two-way ANOVA. The two pieces resulting from the fracture were examined under SEM and their descriptions were reported. When the IDS monomer and resin cement monomer were both GPDM, shear bond strength increased compared to the GPDM baseline. No other combination of IDS monomer and resin cement monomer increased shear bond strength over the respective baseline, no matter whether the monomers were the same or different. The greatest bond strength was in the baseline (no IDS) group of Single Bond Universal Adhesive. The most common fracture mode was an adhesive failure at the IDS and resin cement junction. Cohesive failure frequently occurred in the SuperBond C&B resin cement when it was used as the resin cement. In conclusion, the type of acidic functional monomers in the IDS and resin cement affected the shear bond strength.

Fracture Resistance of Remaining Buccal Cusps in Maxillary Premolar Ceramic Onlay Restorations

Preparation designs for bondable partial coverage restorations are varied. As little as 1 mm of thickness of a remaining buccal cusp can be kept when restoring maxillary premolars with bondable partial coverage restorations.