Formation of functionalized nanoclusters by solvent evaporation and their effect on the physicochemical properties of dental composite resins.
OBJECTIVE
The aim of this work was to study the effect of silica nanoclusters (SiNC), obtained by a solvent evaporation method and functionalized by 3-methacryloxypropyltrimethoxysilane (MPS) and MPS+octyltrimethoxysilane (OTMS) (50/50wt/wt), on the rheological, mechanical and sorption properties of urethane dimethylacrylate (UDMA)/triethylenglycol dimethacrylate (TEGDMA) (80/20wt/wt) resins blend.


METHODS
Silica nanoparticles (SiNP) were silanized with MPS or MPS+OTMS (50/50wt/wt) and incorporated in an UDMA-isopropanol mix to produce functionalized silica nanoclusters after evaporating the isopropanol. The effect of functionalized SiNC on resins rheological properties was determined by large and small deformation tests. Mechanical, thermal, sorption and solubility properties were evaluated for composite materials.


RESULTS
The UDMA/TEGDMA (80/20wt/wt) resins blend with added SiNC (ca. 350nm) and functionalized with MPS showed a Newtonian flow behavior associated to their spheroidal shape, whereas the resins blend with nanoclusters silanized with MPS+OTMS (50/50wt/wt) (ca. 400nm) showed a shear-thinning behavior due to nanoclusters irregular shape. Composite materials prepared with bare silica nanoclusters showed lower compressive strength than functionalized silica nanoclusters. MPS functionalized nanoclusters showed better mechanical properties but higher water sorption than functionalized nanoclusters with both silane coupling agents, MPS and OTMS.


CONCLUSIONS
The solvent evaporation method applied to functionalized nanoparticles showed to be an alternative way to the sinterization method for producing nanoclusters, which improved some dental composite mechanical properties and reduced water sorption. The shape of functionalized silica nanoclusters showed to have influence on the rheological properties of SiNC resin suspensions and the mechanical and sorption properties of light cured composites.
Grupo de Coloides, Instituto de Química, Universidad de Antioquia, Medellín, Colombia; New Stetic S.A., Guarne, Colombia.
Henry A
HA
Rodríguez
Grupo de Coloides, Instituto de Química, Universidad de Antioquia, Medellín, Colombia.
Luis F
LF
Giraldo
Grupo de Coloides, Instituto de Química, Universidad de Antioquia, Medellín, Colombia. Electronic address: herley.casanova@udea.edu.co.
Herley
H
Casanova
D003188:Composite Resins / Q000737:chemistry*; D055119:Elastic Modulus; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008854:Microscopy, Electron; D015394:Molecular Structure; D053761:Nanocomposites / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014783:Viscosity
D003188:Composite Resins; D008689:Methacrylates; D011109:Polymethacrylic Acids; D011140:Polyurethanes; D012821:Silanes; D012997:Solvents; C029824:urethane dimethacrylate luting resin; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; D012822:Silicon Dioxide
Composites; Dental resins; Functionalized silica nanoparticles; Nanoclusters; Restorative materials; Silane coupling agents; Solvent evaporation method