ADHESIVE-COMPOSITE INCOMPATIBILITY, PART II

Cross-Compatibility of Methacrylate-Based Resin Composites and Etch-and-Rinse One-Bottle Adhesives

Cross-compatibility between different combinations of methacrylate-based resin composites and etch-and-rinse one-bottle adhesives was evidenced for products from different manufacturers. This represents a desirable property of adhesives as it allows the flexibility to select different composite systems based on the specific restorative needs.

Conventional dual-cure versus self-adhesive resin cements in dentin bond integrity

During post preparation, the root canal is exposed to the oral cavity, and endodontic treatment may fail because of coronal leakage, bacterial infection and sealing inability of the luting cement.

OBJECTIVE

this study quantified the interfacial continuity produced with conventional dual-cure and self-adhesive resin cements in the cervical (C), medium (M) and apical (A) thirds of the root.

MATERIAL AND METHODS

Forty single-rooted human teeth were restored using Reforpost # 01 conical glass-fiber posts and different materials (N=10 per group): group AC=Adper™ ScotchBond™ Multi-purpose Plus + AllCem; group ARC=Adper™ ScotchBond™ Multi-purpose Plus + RelyX ARC; group U100=RelyX U100; and group MXC=Maxcem Elite. After being kept in 100% humidity at 37°C for 72 hours, the samples were sectioned parallel to their longitudinal axis and positive epoxy resin replicas were made. The scanning electron micrographs of each third section of the teeth were combined using Image Analyst software and measured with AutoCAD-2002. We obtained percentage values of the interfacial continuity.

RESULTS

Interfacial continuity was similar in the apical, medium and cervical thirds of the roots within the groups (Friedman test, p>0.05). Comparison of the different cements in a same root third showed that interfacial continuity was lower in MXC (C=45.5%; M=48.5%; A=47.3%) than in AC (C=85.9%, M=81.8% and A=76.0%), ARC (C=83.8%, M=82.4% and A=75.0%) and U100 (C=84.1%, M=82.4% and A=77.3%) (Kruskal-Wallis test, p<0.05).

CONCLUSIONS

Allcem, Rely X ARC and U100 provide the best cementation; cementation was similar among root portions; in practical terms, U100 is the best resin because it combines good cementation and easy application and none of the cements provides complete interfacial continuity.

Cements and adhesives for all-ceramic restorations

Dental cements are designed to retain restorations, prefabricated or cast posts and cores, and appliances in a stable, and long-lasting position in the oral environment. Resin-based cements were developed to overcome drawbacks of nonresinous materials, including low strength, high solubility, and opacity. Successful cementation of esthetic restorations depends on appropriate treatment to the tooth substrate and intaglio surface of the restoration, which in turn, depends on the ceramic characteristics. A reliable resin cementation procedure can only be achieved if the operator is aware of the mechanisms involved to perform the cementation and material properties. This article addresses current knowledge of resin cementation concepts, exploring the bonding mechanisms that influence long-term clinical success of all-ceramic systems.

An overview of treatment considerations for esthetic restorations: a review of the literature

Controversy persists regarding the treatment planning criteria for esthetic restorations. This article reviews the literature regarding the biocompatibility, marginal adaptation, color matching, patient selection, technique sensitivity, and mode and rate of failure of tooth-colored restorations. A Medline search was completed for the period from 1986 to 2006, along with a manual search, to identify pertinent English peer-reviewed articles and textbooks. The key words used were amalgam, posterior composite resin, ceramic inlays/onlays, CEREC, porcelain laminate veneers, all-ceramic crowns, and all-ceramic fixed partial dentures.