ABSTRACT
Abstract Although fiber-reinforced composites are commonly used in dental practice, whether fiber-reinforced crowns and fixed partial dentures can be used as definitive prostheses remains to be determined. This study used scanning electron microscopy to evaluate the load-bearing capacity of non-reinforced and fiber-reinforced composite (FRC) molar crowns prepared by computer-aided design/computer-aided manufacturing (CAD/CAM). The crowns were fabricated from three empirical FRC blocks, one empirical composite block, and one commercial ceramic block. The FRC resin was prepared by mixing BaO silicate particles, E-glass fiber, and dimethacrylate resin. Specimens were divided into five groups (n = 10), differing in the amounts of filler, resin, and fiber. Crowns were statically loaded until fracture. One-way analysis of variance and Tukey's post hoc multiple comparison tests were used for statistical analyses. The groups showed significant differences in load-bearing capacity; empirical bidirectional FRC resin blocks had the highest capacity, while commercial ceramic blocks had the lowest capacity. Molar crowns formed from FRC resin blocks had higher load-bearing capacity compared to non-reinforced composite resin and ceramic blocks. These results show that fiber reinforcement increased the load-bearing capacity of molar crowns.
Subject(s)
Humans , Weight-Bearing , Computer-Aided Design , Composite Resins/chemistry , Crowns , Reference Values , Surface Properties , Materials Testing , Microscopy, Electron, Scanning , Ceramics/chemistry , Reproducibility of Results , Dental Prosthesis Design , Evaluation Study , MolarABSTRACT
Abstract Nowadays, demand for esthetic restorations has risen considerably; thus, nonmetal esthetic posts made of either high-strength ceramics or reinforced resins, such as fiber-reinforced resin posts, have become more and more popular. Important characteristics of fiber-reinforced posts involve a modulus of elasticity similar to dentin and their ability to be cemented by an adhesive technique. A total of 36 maxillary incisors were divided into four groups. In this study, four adhesively luted fiber-reinforced (glass fiber, quartz glass fiber, zirconia glass fiber and woven polyethylene fiber ribbon) post systems were used. Post spaces were prepared by employing drills according to the protocol established for each group, and each post was adhesively luted with one of three adhesive systems. Three segments per root apical to the cementoenamel junction (CEJ) were obtained by sectioning the root under distilled water with a carbon spare saw. The samples (total of 108 sections) were 2.0±0.1 mm in thickness and they were stored individually in black film canisters with sterile distilled water. In order to determine the bond strength, the bonding area of each specimen was measured, and specimens were attached to a device to test microtensile strength at a speed of 1 mm/min. The analyses revealed no statistically significant differences between the adhesive systems and fiber-reinforced posts. (P> 0.05). However, the coronal portion of the root dentin had the highest bond strength. Adhesive systems used along with fiber-reinforced resin posts demonstrated reliable bonding.