PMMA-based composite materials with reactive ceramic fillers: IV. Radiopacifying particles embedded in PMMA beads for acrylic bone cements

Abstract

New acrylic bone cements were prepared from alumina particles previously treated by 3-(trimethoxysilyl)propylmethacrylate (gamma-MPS) and embedded in poly(methylmethacrylate-co-ethylacrylate) beads with about 7 mol% of ethyl acrylate repeating units. The encapsulation was performed through a conventional suspension polymerization process. The influence of (i) the concentration of the dispersion stabilizer and (ii) the alumina content upon the shape, size, and size distribution of the acrylic beads was studied. Cements were prepared from each batch by hand-mixing alumina-filled acrylic beads with a liquid monomer mixture containing methyl methacrylate, n-butyl methacrylate, and N,N-dimethyl-p-toluidine. Benzoyl peroxide was previously added to the solid part. The powder-to-liquid ratio was equal to 2 for each formulation. Compressive strength of cured cement decreases with alumina content, whereas compressive modulus remains roughly constant. These results are in contradiction to those obtained for cements based on a mixture of gamma-MPS-treated alumina and unfilled acrylic beads. Nevertheless, they are interpreted in terms of alumina arrangement in the cement. In the first case, alumina particles contribute to the reinforcement of the dispersed acrylic phase, with poor benefits for the whole materials. In the second case, they allow the reinforcement of the continuous acrylic phase and, therefore, the cement's one.

Effect of different amounts of 3-methacryloxypropyltrimethoxysilane on the flexural properties and wear resistance of alumina reinforced PMMA

“…In order to overcome these problems, several attempts were made to modify and improve the strength and hardness of the PMMA [7][8][9][10] . These attempts included the addition of fi ller particles such as zirconia 8) , glass fi ber 9) and alumina 7,10) . Previously, the addition of alumina into PMMA resulted in increase thermal conductivity and hardness 7,10) .…”

“…In the 0.0 mass% MPS group, the fl exural properties were low due to no bonding between fi ller and resin matrix. This result was in accordance with the previous studies 10,14,16) which suggested that fi ller particles should be silanized effectively to reinforce PMMA.…”

“…However, some problems such as denture fracture 2,3) and wear of the denture teeth still exist [4][5][6] . In order to overcome these problems, several attempts were made to modify and improve the strength and hardness of the PMMA [7][8][9][10] . These attempts included the addition of fi ller particles such as zirconia 8) , glass fi ber 9) and alumina 7,10) .…”

“…These attempts included the addition of fi ller particles such as zirconia 8) , glass fi ber 9) and alumina 7,10) . Previously, the addition of alumina into PMMA resulted in increase thermal conductivity and hardness 7,10) . However, the improvement of mechanical properties by blending alumina into PMMA has not been yet confi rmed.…”

Injectable acrylic bone cements for vertebroplasty with improved properties

“…These results indicate that, for silanated fillers, a significantly higher amount of PMMA chains were covalently bonded to the surface of the filler through silane molecules. According to Abboud and co-workers 11,24,25 the silanation of Al 2 O 3 filler with ␥-MPS proceeds via hydroxyl groups corresponding to physisorbed water on the filler surface, as shown in the schematic representation of Figure 9. Before silane treatment, the filler surface is relatively hydrophilic and poorly wetted by the organic monomer.…”