Journal of Applied Oral Science · 2010 · 156 citations · 22 references
EngineeringMaterials EngineeringMaterials ScienceMaterials ProcessingPolymer EngineeringSurface EngineeringComposite MaterialsComposite ResinsSurface FinishingSurface MetrologySurface RoughnessSurface Roughness EffectsComposite Resin Surface CharacteristicsFiller MaterialsFiller Particle Size EffectsFiller Shape EffectsMaterial Surface FinishRoughnessRoughness ParametersSurface Roughness Parameters
The study aimed to assess how filler size and shape influence the surface roughness of experimental resin‑composite series. Thirty‑three disc specimens were light‑cured, stored in water for 3 months, and their Ra, Rmax, and Sm values were measured with a contact profilometer and analyzed by one‑way ANOVA with Scheffé post‑hoc testing. Spherical fillers produced the smoothest surfaces, with Ra values rising linearly (r² = 0.82) as filler size increased, while irregular shapes and larger fillers yielded higher roughness; horizontal roughness was unaffected by size or shape, indicating that filler particle size and shape markedly affect surface roughness.
OBJECTIVE: The purpose of this study was to evaluate the effect of different filler sizes and shapes on the surface roughness of experimental resin-composite series. MATERIAL AND METHODS: Thirty-three disc-shaped specimens of the series (Spherical-RZD 102, 105, 106, 107, 114 and Irregular-RZD 103, 108, 109, 110, 111, 112) were prepared in a split Teflon mold and irradiated with an halogen light-curing unit (450 mW/cm² for 40 s) at both top and bottom surfaces. The specimens were stored for 3 months in distilled water. The surface roughness values in form of surface finish-vertical parameter (Ra), maximum roughness depth (Rmax) and horizontal roughness parameter (Sm) were recorded using a contact profilometer. The data were analyzed by one-way ANOVA and the means were compared by Scheffé post-hoc test (a=0.05). RESULTS: The lowest surface roughness (Ra) was observed in S-100 (0.079±0.013), while the roughest surface was noted in I-450/700/1000 (0.125±0.011) and I-450/1000 (0.124±0.004). The spherical-shape series showed the smoothest surface finish compared to the irregular-shape ones with higher significant difference (p>0.05). The vertical surface roughness parameter (Ra) values increased as the filler size increased yielding a linear relation (r²=0.82). On the contrary, the horizontal parameter (Sm) was not significantly affected by the filler size (r²=0.24) as well as the filler shape. CONCLUSIONS: Filler particle's size and shape have a great effect on the surface roughness parameters of these composite series.
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E S Gadelmawla, M M Koura, T.M.A. Maksoud et al. · Journal of Materials Processing Technology · 2002 · 1.9K citations