TITLE:
A High-Strength Cement System for Improved Dental Restoratives
AUTHORS:
Dong Xie, Jun Zhao, Yiming Weng
KEYWORDS:
Poly(acrylic acid); Molecular Architecture; Glass-Ionomer Cement; Atom-Transfer Radical Polymerization; Mechanical Strength
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.2 No.3,
March
18,
2014
ABSTRACT: We have developed and
studied a novel high-strength glass-ionomer cement system composed of
poly(acrylic acid) with different molecular architectures. These poly(acrylic
acid) polymers were synthesized via ATRP technique. The effects of arm number
and branching on reaction kinetics, viscosity, and mechanical strengths of the
formed polymers and cements were evaluated. The results showed that unlike the
star-shaped polymer synthesis both hyperbranched and star-hyperbranched polymers syntheses proceed slowly at the
early stage but accelerate at the later stage. The higher the arm number and
initiator concentration are, the faster the ATRP
reaction was. It was also found that the higher the arm number and branching
that the polymer had, the lower the viscosity of the polymer aqueous solution is and the lower the mechanical strengths of the formed
cement are. The mechanical
strengths of three synthesized polymers-composed experimental cements were very
similar to each other but much higher than those of Fuji II LC. The
experimental cements were 31% - 53%
in CS, 37% - 55%
in compressive modulus, 80% - 126%
in DTS, 76% - 94% in FS, 4% - 21% in FT and 53% - 96% in KHN higher than
Fuji II LC. For wear test, the experimental cements were only 5.4% - 13% of abrasive and 6.4% - 12% of attritional wear
depths of Fuji II LC in each wear cycle. The one-month aging study also showed that
all the experimental cements increased their CS continuously during 30 days,
unlike Fuji II LC.