Residual Monomer of Restorative Resins

¹ Indiana University School of Dentistry, Indianapolis, Indiana

The residual monomer content of three commercial restorative autopolymerizing resins was investigated as related to time and monomer-polymer ratio. Two of the materials polymerized rapidly with little change in residual monomer being demonstrated after the first hour. The third material polymerized more slowly with leveling of the monomer content occurring at 1 week. Alteration of the monomer-polymer ratio did not affect the general patterns of polymerization of the individual resins. However, the amount of free-monomer present at 1 hour did seem to bear a relationship to the original ratio, for, when the amount of original monomer was increased, a subsequent rise in residual monomer occurred. The reverse was also true.