Keywords: dental composites, surface morphology, AFM, TEM, surface roughness, resin based composites, inorganic fillers, hydroxyapatite, surface quality, glass filler particles, dentistry, teeth
Characterisation of surface organisation and morphology of some new experimental dental resin–based composites
The aim of this work was to investigate the morphology and to determine the roughness of a series of three new experimental resin–based composite materials containing different inorganic fillers using the AFM technique. Dental composites with photochemical initiation of polymerisation were prepared using the same resin consisting of synthesised aromatic dimethacrylic oligomers mixture containing Bis–GMA monomer – 2,2–bis[4–(2–hydroxy–3–methacryloyloxypropoxy) phenyl]–propane and the corresponding Bis–GMA dimer and triethyleneglicol dimethacrylate. The inorganic fillers used in the composites were: 1) a hybrid filler consisting of two superficially active glasses; 2) a new synthesised hydroxyapatite; 3) a commercial hydroxyapatite. From the point of view of the surface uniformity, we can conclude that the smoothest surface results from the composite based on synthesised hydroxyapatite, followed by the composite based on commercial hydroxyapatite, the highest roughness being observed for the composite based on glass filler particles. All three composite materials present compact structures of undermicronic particles uniformly assembled.