Polymeric calcium phosphate cements derived from poly(methyl vinyl ether-maleic acid).
OBJECTIVE
The purpose of this study was to assess the feasibility of forming polymeric calcium phosphate cements from a mixed powder of dicalcium phosphate/tetracalcium phosphate or only tetracalcium phosphate and poly(methyl vinyl ether-maleic acid) (PMVE-Ma), and to study their setting reaction.


METHODS
The setting reaction process of the polymeric cements was evaluated by mechanical strength tests, infrared spectroscopy and x-ray diffraction analysis and compared with that of a water-setting calcium phosphate cement. The mechanical strength data were analyzed using ANOVA and Scheffé's multiple comparisons test.


RESULTS
Cements prepared from the mixed powder and 25-30 wt% aqueous solutions of PMVE-Ma had high mechanical strength after 24 h storage in distilled water at 37 degrees C. The hardening mechanism depended on an acid-base reaction between the carboxyl groups of PMVE-Ma and the mixed powder, especially its tetracalcium phosphate component. The formation of hydroxyapatite in the polymeric calcium phosphate cement was not detected and is apparently inhibited as a result of the competing reaction of PMVE-Ma with the mixed powder.


CONCLUSIONS
The cement-forming reaction was significantly faster than that of a water-setting calcium phosphate cement and slower than that observed with the mixed powder and polyacids such as poly(acrylic acid). The characteristics of the polymeric cements suggest that the materials may be useful in cavity lining or endodontic sealing.
Matsuya
Y
Y
Department of Conservative Dentistry II, Faculty of Dentistry, Kyushu University, Fukuoka, Japan.
Antonucci
J M
JM
Matsuya
S
S
Takagi
S
S
Chow
L C
LC
D000704:Analysis of Variance; D002126:Calcium Hydroxide / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003738:Dental Cements / Q000737:chemistry*; D004339:Drug Compounding; D006244:Hardness; D008277:Magnesium Oxide / Q000737:chemistry; D008298:Maleates / Q000737:chemistry*; D008422:Materials Testing; D008903:Minerals / Q000737:chemistry; D018583:Pliability; D011076:Polycarboxylate Cement / Q000737:chemistry; D011145:Polyvinyls / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013718:Tensile Strength; D013997:Time Factors; D014867:Water; D015034:Zinc Oxide / Q000737:chemistry
D002130:Calcium Phosphates; D003738:Dental Cements; D008298:Maleates; D008903:Minerals; D011076:Polycarboxylate Cement; D011145:Polyvinyls; C058026:polyvinylmethoxyethylene-maleic anhydride copolymer; D014867:Water; D008277:Magnesium Oxide; C025702:Dycal; C040235:Ketac-cem; D002126:Calcium Hydroxide; D015034:Zinc Oxide