title: Effect of filler particles on surface roughness of experimental composite series.
abstract: 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.
authors.affiliation: Operative Dentistry Division, Conservative Dental Science (CDS) Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia. hanadi.marghalani@gmail.com
authors.forename: Hanadi Yousif
authors.initials: HY
authors.lastname: Marghalani
mesh_terms: 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
chemical_list: 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