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The first paper in this series presented a categorization of dentinal adhesive systems that was organized roughly according to chronology, chemistry, and shear bond strength values. Category I dentinal adhesives demonstrate the lowest shear bond strength values, approximately 5 to 7 MPa. Category II dentinal adhesives, including experimental ferric and aluminum oxalate pretreatments and two commercial products, demonstrate shear bond strength values between 8 and 14 MPa. This second category of dentinal adhesives is the subject of this paper. An attempt is made to draw a parallel between the penetrative ability of the adhesive (the wettability of the dentinal substrate) and the efficacy of the adhesive bond as determined by shear bond strength values. Category III dentinal adhesives will be discussed in another paper. [ABSTRACT FROM AUTHOR]

The purpose of this study was to test the adherence strength of oxides to some silver-free high-palladium alloys, and to compare the results to values obtained from Au-Pd and Ni-Cr metals. The results showed that the adherence strengths of the oxides were greater than the reported cohesive strength of opaque porcelain. This would indicate that the oxides formed on the alloys examined in this study are sufficiently adherent to their substrates to produce adequate porcelain bonds. [ABSTRACT FROM AUTHOR]

The article focuses on an in vitro study that measures the retentive strength of etched porcelain bridges bonded to the abutment teeth with composite resin. The study aims at determining the force necessary to fracture etched porcelain bridges and to compare the strength of five different types of abutment tooth attachments. 70 porcelain bridges, extending from maxillary central incisor to maxillary lateral incisor, were constructed. The specimens were separated into seven groups of 10 specimens each. Multiple comparisons were analyzed using the Newman-Keuls technique. An analysis of variance indicated significant differences among the means. Results showed that the porcelain/metal substructure bridge with box preparations in the abutment teeth provided the greatest strength.

Objective: To test the hypothesis that fluoride prophylactic agents do not affect the fracture strength and fracture morphology of the tie-wing complex of ceramic brackets. Materials and Methods: The fracture strength of the distal incisal tie-wing of two polycrystalline brackets, Clarity and Mystique, and a monocrystalline bracket, Inspire, was measured after the brackets were exposed to either Prevident, Phos-flur gel, or distilled water (control). Scanning electron microscopy was used to qualitatively evaluate the tie-wing intact and fractured surfaces. Results: A two-way analysis of variance and Fisher-Hayter post hoc test, α = .05, indicated a significant decrease in tie-wing fracture strength following both fluoride treatments when compared with the distilled water control only with the monocrystalline bracket. None of the bracket brands exhibited any qualitative differences in the tie-wing intact or fracture surfaces as a function of fluoride treatment. Conclusions: The hypothesis is rejected. Based on the results, using topical fluoride agents with monocrystalline brackets might be contraindicated because of increased tie-wing fracture susceptibility. [ABSTRACT FROM AUTHOR]