No technique or material, when individually considered, was capable of achieving the mechanical strength of the sound teeth; however, the association of reattachment technique Circumferential chamfer with bonding system Single Bond could approximate the immediate impact strength of the restored teeth to that observed in the sound teeth.

This study evaluated protocols to eliminate acetone from dental adhesives and their effect on the kinetic of water sorption and percent of conversion of these adhesives. Experimental methacrylate-based adhesives with increasing hydrophilicity (R2, R3, R5) were used as reference materials. Primer-like solutions were prepared by addition of 50 wt% acetone. Acetone elimination was measured gravimetrically before and after: a spontaneous evaporation, an application of air-drying at room temperature or application of 40°C air-drying. Protocols were performed from 15 to 60 s. Specimens of adhesive/acetone mixtures were photo-activated and tested for degree of conversion, water sorption and solubility. Data were analyzed by ANOVA and Bonferroni's tests (α = 0.05). Complete acetone elimination was never achieved, but it was significantly greater after the 40°C air-drying application. Higher acetone elimination was observed for the least hydrophilic adhesive. Longer periods for acetone evaporation and heated air-stream can optimize polymerization and reduce the water sorption/solubility of adhesive system models.

The use of post and core systems has become an excellent alternative for restoring endodontically treated teeth. The aim of this study was to evaluate the von Mises, maximal compressive and tensile stresses distribution using the Finite Element Method (FEM) on human teeth restored with different post and core systems. The analysis was made on endodontically treated maxillary central incisors. The post systems used in this investigation were the stainless steel or titanium Flexi Post/Flexi Flange. Composite resin was used as core material and resin cement was the cement material of choice to seat a full porcelain crown. The bi-dimensional mathematical model was created from pictures taken from an intact human maxillary central incisor and prefabricated posts. This image was transferred to a personal computer in the MSC/Nastran 4.5 software. A static and linear analysis treatment was performed when a 45 load of 100 N was applied on the lingual surface of the tooth. Based on the results obtained, it can be concluded that the post design and its material can alter the stress pattern distribution.