Synthesis and Evaluation of Novel Multifunctional Oligomers for Dentistry

Abstract

A new type of multifunctional oligomer was synthesized, and its potential as a base monomer in dental composite formulations was evaluated. The oligomer of ethoxylated bis-phenol A diacrylate (OEBPA) was prepared in good yield by a formaldehyde insertion/ condensation reaction. Although double bonds along the oligomer backbone are arranged in pairs such that cyclopolymerization is possible, it is not presently known whether this process plays a significant role in the polymerization. Indirect evidence supporting efficient cyclopolymerization involves the reduced polymerization shrinkage observed for polymerized OEBPA relative to polymers of other monomers used as base resins. Photo-cured composites containing either OEBPA, BIS-GMA, or ethoxylated bis-phenol A dimethacrylate (EBPADM) as base resin and TEGDMA as diluent were compared. While the resulting diametral tensile and transverse strengths did not differ significantly, the values for the energy absorbed to failure indicated that the OEBPA- and EBPADM-based formulations yielded composites with somewhat greater toughness than that of the BIS-GMA material. This multifunctional oligomer offers mechanical strength and conversion values that are comparable with those of existing base resin monomers while providing an approximate 30% reduction in polymerization shrinkage.

Get full access to this article

View all access options for this article.

References

Antonucci, J.M. ; Stansbury, J.W. ; and Venz, S. (1990): Synthesis and Properties of a Polyfluorinated Prepolymer Multifunctional Urethane Methacrylate. In: Progress in Biomedical Polymers, C.G. Gebelein and R.L. Dunn , Eds., New York: Plenum Press, pp. 121-131.

Butler, G.B. (1975): Perspectives in Cyclopolymerization. In: Proceedings of the International Symposium on Macromolecules, E.B. Mano, Ed., New York: Elsevier Scientific Publishing Company, pp. 57-76.

Cranshaw, A. and Butler, G.B. (1958): The Formation of Linear Polymers from Diene Monomers by a Cyclic Polymerization Mechanism. II. Polyacrylic Anhydride and the Derived Polyacrylic Acid, J Am Chem Soc 80:5464-5466.

Hwa, J.C.H. ; Fleming, W.A. ; and Miller, L. (1964): Acrylic Anhydrides and Polymers Derived Therefrom , J Polym Sci (Part A) 2 :2385-2400.

Jones, J.F. (1958): Cyclopolymerization. II. Polyacrylic Anhydride , J Polym Sci 33:15-20.

Mathias, L.J. and Dickerson, C.W. (1990): Oligoether-ester Crosslinking Agents via a-Substitution of Bisacrylates, J Polym Sci (Part C) Polym Lett 28:175-179.

Mathias, L.J. and Kusefoglu, S.H. (1987): New Difunctional Methacrylate Ethers and Acetals: Readily Available Derivatives of a-Hydroxymethyl Acrylates, Macromolecules 20:2039-2041.

Mathias, L.J. ; Kusefoglu, S.H. ; and Ingram, J.E. (1988): Cyclopolymerization of the Ether of Methyl a-(Hydroxymethyl)acrylate , Macromolecules 21:545-546.

Miller, W.L. ; Brey, W.S. ; and Butler, G.B. (1961): Proton Magnetic Resonance Studies of the Microstructure of Polymethacrylic Anhydride, J Polym Sci 54:329-342.

10.

Patel, M.P. ; Braden, M. ; and Davey, K.W.M. (1987): Polymerization Shrinkage of Methacrylate Esters , Biomaterials 8:53-56.

11.

Ruyter, I.E. and Rødsrud, P.G. (1988): Cyclopolymerization of Dimethacrylate Monomers , J Dent Res 67:346, Abst. No. 1867.

12.

Stansbury, J.W. (1989): Synthesis and High Conversion Polymerization of Novel Difunctional Monomers, JDent Res 68:248, Abst. No. 535.

13.

Stansbury, J.W. (1990a): Cyclopolymerizable Monomers for Use in Dental Resin Composites, J Dent Res 69:844-848.

14.

Stansbury, J.W. (1990b): Synthesis and Polymerization of Difunctional and Multifunctional Monomers Capable of Cyclopolymerization, Polym Prepr (Am Chem Soc, Diu Polym Chem) 31:503-504.

15.

Stansbury, J.W. (1990c): Evaluation of a New Multifunctional Oligomer for Dental Composites, J Dent Res 69:208, Abst. No. 794.