Journal of Dental Research, Vol 71, 2-6, Copyright © 1992 by International & American Associations for Dental Research Online Journals
Radiopacity and physical properties of titanium-polymethacrylate composite
H. Matsumura, M. Sueyoshi and M. Atsuta
Department of Fixed Prosthodontics, Nagasaki University School of Dentistry, Japan.
Titanium-polymethacrylate composite was prepared as an x-ray-opaque filler
for composite core materials. The base monomers of the composite were
2,2-bis [4-(3-methacryloyloxy-2-hydroxypropoxy) phenyl] propane (Bis-GMA)
and triethyleneglycol dimethacrylate (TEGDMA). Pure titanium powder was
used as a radiopaque element. Two functional methacrylates--isopropyl
dimethacryloyl isostearoyl titanate (KR-7) and 4-methacryloyloxyethyl
trimellitate anhydride (4-META)--were adopted as couplers of titanium
powder. The radiopacity of composites was determined in terms of their
equivalent thickness of aluminum per unit thickness of material.
Compressive and transverse strengths of the composites were measured by use
of coupled and untreated titanium fillers. The composites that contained
70% and 80% titanium by weight showed more radiopacity than enamel and less
than amalgam. Radiopacity was controlled by the content of titanium filler
in the composite. The decrease in compressive and transverse strengths of
the composites was 0.7 to 15.9% and 43.7 to 52.9%, respectively, after one
year's immersion in water. The decrease in transverse strength was
remarkable; however, this deterioration was diminished by use of both KR-7
and 4-META as couplers for titanium. Thus, prepared
titanium-polymethacrylate composite may be used as a radiopaque composite
filler for self-curing composite core materials.
