Resin-based Luting Agents Research Articles

Contemporary perspectives on post-core systems.

The challenge of restoring endodontically-treated teeth has spawned a considerable diversity in foundation restorations and a plethora of publications in the dental literature. Moreover, it seems that an inverse relationship has developed between the escalating complexity in selecting a post-core system and the volume of reliable scientific data upon which clinicians base their treatment decisions. In the quest to restore aesthetics, function, and reduce the risk of treatment failure there is now a much greater emphasis on the preservation of sound tooth structure, tooth isolation for intracanal procedures, sealing the root canal and adapting the advantages and limitations of dental materials to the presenting clinical situation. The relatively recent introduction of metal-free posts into mainstream prosthodontics has added an aesthetic dimension to treatment planning. New adhesive systems and resin-based luting agents have the potential to create a genuine adhesive continuum between the tooth and post-core complex. While these developments may have significant ramifications with respect to treatment prognosis, the long-term clinical performance of contemporary post-core systems is unclear.

Influence of film thickness on joint bend strength of a ceramic/resin composite joint

Objectives. The purpose of this study was to evaluate the influence of different film thicknesses of resin composite luting agents on the joint bend strength of a ceramic/resin interface.Methods. Mirage FLC (Chamelon Dental Products) and Vita Cerec (Coltène AG) duo cement were used in combination with the ceramic materials, Mirage and Vita Cerec blocks. Cement layers with thicknesses of 20 μm, 50 μm, 100 μm and 200 μm were light-cured with a high-intensity curing light. Ten specimens of each ceramic/cement combination and thickness provided a total of 80 complete test specimens. Each specimen was placed in a four-point bending jig mounted in a universal tensile testing machine and underwent loading. A paired two-tailed Student's t-test was used to evaluate differences between different series of film thicknesses and resin cement combinations.Results. Within each ceramic-cement combination, the bond strength values were significantly lower for the 20 μm film than the thicker films.Significance. Taking into account the physical and clinical properties of resin-based luting agents, available knowledge indicates that a marginal gap on the order of 50–100 μm seems to optimize performance.

Factors affecting the adherence energy of experimental resin cements bonded to a nickel-chromium alloy.

Reliable adherence of resin-based cements is of prime importance for the longevity of cemented restorations. The present study investigated whether a relationship exists between adherence energy to a metal substrate and the degree of cross-linking and wetting characteristics of resin-based luting agents. The adherence energies between a sand-blasted metal surface and a series of experimental resin cements were measured by means of the wedge test. The degree of cross-linking was calculated from the monomer composition of the resin cements. The measured wetting characteristics were work of adhesion and surface tension, and their dispersive and polar components. Adherence energy varied between 22 and 81 J/m2 and was influenced by the nature of the resin cements: Those with a low degree of cross-linking resulted in high adherence values. Furthermore, resin cements whose monomers were relatively polar gave rise to high adherence values. Although other metals may not behave in exactly the same way, these results may help in the formulation of new, more retentive resin cements.

Bonding of resin cements to an aluminous ceramic: A new surface treatment

Objectives. The purpose of the work reported here was to develop a surface treatment of an alumina-based ceramic (In Ceram) that would make reliable bonding to a resin-based luting agent possible. Methods. The surface treatment studied was the application of a suspension of a fine-grained, refractory powder, which after drying was sintered to the surface at 960°C. The adherence potential of the surface was determined by measurement of bond energy. Results. It was found that the surface treatment, in conjunction with a heat-treated, silane coupling agent, resulted in mean bond energies of 47 (±19), 56 (±22), and 525 (±116) J/m 2 for the three resin cements studied. Significance. It was concluded that the new surface treatment makes reliable bonding possible, which may allow new indications for this material.