Objective. To compare handmade and computer-aided design–computer-aided manufacturing (CAD-CAM)-fabricated fixed dental prostheses (FDPs) composed of a particulate filler composite. Material and methods. Handmade FDPs were made of restorative composite (Z 100) and CAD-CAM-fabricated FDPs were made of commercial CAD-CAM blocks (VITA Temp) and two experimental CAD-CAM blocks of particulate filler composite. Experimental CAD composite A was prepared by mixing 31.2 wt.% of dimethacrylate resin with 68.7 wt.% of filler particles of barium oxide silicate (BaSiO2). Experimental CAD composite B was prepared by mixing 25.6 wt.% of dimethacrylate resin with 74.3 wt.% of filler particles of BaSiO2. Six groups were fabricated (n = 6 in each); FDPs were statically loaded until final fracture. Results. Experimental CAD composites A and B revealed the highest load-bearing capacity of the FDPs, while Z 100 showed the lowest. Conclusion. FDPs made of experimental CAD composite blocks showed higher load-bearing capacities than handmade commercial composites and commercial blocks.
1 February 2013 in The Journal of Prosthetic Dentistry
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.