Effect of filler particles on surface roughness of experimental composite series.
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.


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/cm(2) 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 (R(a)), maximum roughness depth (R(max)) and horizontal roughness parameter (S(m)) were recorded using a contact profilometer. The data were analyzed by one-way ANOVA and the means were compared by Scheffé post-hoc test (alpha=0.05).


RESULTS
The lowest surface roughness (R(a)) 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 (R(a)) values increased as the filler size increased yielding a linear relation (r(2)=0.82). On the contrary, the horizontal parameter (S(m)) was not significantly affected by the filler size (r(2)=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.
Marghalani
Hanadi Yousif
HY
Operative Dentistry Division, Conservative Dental Science (CDS) Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia. hanadi.marghalani@gmail.com
D000537:Aluminum Oxide / Q000737:chemistry; D017609:Barium Compounds / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D017554:Carbon Compounds, Inorganic / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D055117:Curing Lights, Dental / Q000145:classification; D003764:Dental Materials / Q000737:chemistry* / Q000528:radiation effects; D003775:Dental Polishing / Q000379:methods; D005898:Glass / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D053761:Nanocomposites / Q000737:chemistry; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D017655:Silicon Compounds / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry
D017609:Barium Compounds; D017554:Carbon Compounds, Inorganic; D003188:Composite Resins; D003764:Dental Materials; D008689:Methacrylates; D011109:Polymethacrylic Acids; D011140:Polyurethanes; D012821:Silanes; D017655:Silicon Compounds; C102738:barium glass filler; D014867:Water; C029824:urethane dimethacrylate luting resin; C020946:triethylene glycol dimethacrylate; C017492:methacryloxypropyltrimethoxysilane; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; D012822:Silicon Dioxide; D000537:Aluminum Oxide; C022088:silicon carbide