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The aim of this study was to estimate the flexural properties of three kinds of experimental fiber-reinforced composite (FRC) posts and to evaluate their potential use as posts. Experimental FRC posts were fabricated with glass, aramid, and UHMWP fibers. Commercial FRC posts were used for comparison. A three-point bending test was performed at a crosshead speed of 1 mm/min. Experimental glass fiber posts showed significantly higher flexural strengths and moduli than aramid and UHMWP posts. Experimental UHMWP posts demonstrated superior toughness to the commercial posts. The glass fiber posts displayed stiff, strong and brittle features, while the UHMWP posts were flexible, weak and ductile. The flexural properties of the aramid posts fell between those of the glass and UHMWP posts. In conclusion, the glass fiber posts proved excellent in flexural strengths and moduli. However, the superior toughness of UHMWP fibers suggests the possibility of their use as posts in combination with glass fibers. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effects of plasma treatment on adhesion between fiber-reinforced posts and a composite core material. Two types of posts, methacrylate-based (FRC Postec) and epoxy resin-based (DT Light-Post), were treated with oxygen plasma (O2), argon plasma (Ar), nitrogen plasma (N2), or helium mixed with nitrogen plasma (He+N2) using a radio-frequency generator before bonding to a methacrylate-based composite. Pull-out tests were performed using a universal testing machine. Surface roughness of each group was evaluated using a profilometer. On tensile-shear bond strength, statistical analysis revealed that the type of post, type of plasma treatment, and their interaction significantly influenced the results (pc0.05). Tukey's test revealed significant differences in tensile-shear bond strength between the control and other plasma treatment groups (p<0.05). On surface roughness, Tukey's test revealed significant differences between the control group and the Ar group (p<0.05) with DT Light Post. Plasma treatment appeared to increase the tensile-shear bond strength between post and composite. [ABSTRACT FROM AUTHOR]

This study evaluated the three-year clinical performance of Class V restorations made of a polyacid-modified resin composite, Dyract. Ninety-two Class V carious lesions in 28 patients were restored with Dyract. Restorations were clinically evaluated at baseline, first, second, and third year recall visits, according to the modified Ryge criteria by two experienced, calibrated examiners. Retention rate after three years it. Class V carious restorations was 92.4%, with only seven failed restorations. Color change and marginal discoloration in restorations were found to be statistically significant (p=0.013 and p<0.001, respectively) at the end of third year, but none of the affected restorations required replacement. The results of this study revealed that at the end of three years, Dyract exhibited good clinical success rate but significant color change and marginal discoloration in Class V carious lesions. [ABSTRACT FROM AUTHOR]

To investigate the pre-clinical relevancy of a machinable composite, its physical properties were evaluated and compared with a machinable ceramic and two indirect composites. A machinable resin composite (GN-I composite, CO), a machinable ceramic (GN-I ceramic, CE), and two resin composites (Artglass dentin, AG; Estenia dentin. ST) were used. Compressive strength, diametral tensile strength, flexural strength, elastic modulus, and fracture load of standardized, premolar crown- shaped specimens were determined. In terms of compressive strength, diametral tensile strength, and flexural strength, AG showed significantly lower values than the other three materials In terms of fracture load, specimens with 15 mm thick wall showed a higher value than those with 10 mm thick wall and the value decreased in the order of ST, CE, CO, and AG Marginal tipping was also observed in ET and CE. Within the limits of the current study, CO showed physical properties favorable for constructing esthetic restorations [ABSTRACT FROM AUTHOR]