ABSTRACT
OBJECTIVES: The aim of this study was to evaluate surface roughness and hardness of a nanofiller GIC, a resin-modified GIC, three conventional GICs, and a silver-reinforced GIC. METHODS: For each material, 11 spcecimens were prepared and then stored in distilled water at 37 °C for 24 h. The surface roughness of 5 specimens was measured using a surface profilometer before polishing and after polishing with coarse, medium, fine, superfine aluminum oxide abrasive Sof-Lex discs respectively. The hardness of the upper surfaces of the remaining 6 specimens was measured with a Vickers microhardness measuring instrument. RESULTS: All tested GICs showed lower surface roughness values after the polishing procedure. Surface finish of nanofiller GIC was smoother than the other tested GICs after polishing. This was followed by resin-modified GIC, Fuji II LC; then silver-reinforced GIC, Argion Molar, conventional GICs, Aqua Ionofil Plus, Fuji IX, and Ionofil Molar, respectively. The result of the hardness test indicated that the microhardness value of silver-reinforced GIC was greater than that of the other GICs. When the hardness values of all tested GICs were compared, the differences between materials (except Aqua Ionofil Plus with Ionofil Molar and Ketac N100 with Fuji II LC (P>.05)) were found statistically significant (P<.05). CONCLUSIONS: According to the results of this study, it can be concluded that the differences in the composition of GICs may affect their surface roughness and hardness.
ABSTRACT
OBJECTIVES: The aim of this study was to investigate the effects of fiber-reinforced resin burs on the surface roughness of a nanofilled composite. METHODS: Average surface roughness values (Ra, mum) were measured using a surface profilometer and surface textures after finishing procedures were evaluated using a scanning electron microscope (SEM). Thirty cylindrical specimens were prepared using sectional teflon molds. A nanofilled composite was chosen. After the preparation specimens were divided into three subgroups randomly. After profilometric measurements, representative samples of the mentioned finishing procedures were selected and SEM analyses were carried out. RESULTS: Mylar strip group was statistically different from the other two groups (P<.05). The smoothest surfaces occurred when composite resin samples were light cured against the strips. On the other hand there was no statistical difference between fiber-reinforced resin burs and Sof-Lex discs (P>.05). For fiber-reinforced resin burs scratches and pitting which may be due to plucking of the filler particles during finishing were observed on the surface topography of the composite resin material. On the other hand, for the Sof-Lex discs although scratches were noticed on the surface topography, no pitting was observed. CONCLUSIONS: Fiber-reinforced resin burs can be preferred for the grinding of composite surplus in interproximal surfaces, where the use of Sof-Lex discs can be harmful to soft tissues.
