Wire reinforcement of acrylic resin prostheses

Abstract

lhe wishbone fracture of acrylic resin prostheses is a common problem for pedodontic and orthodontic patients.‘.4 In mandibular prostheses, less bulk and the necessity of thinner sections in the anterior region for patient comfort make acrylic resin particularly susceptible to fracture. Two other factors add to the problem: (1) fabrication is usually by the salt-and-pepper technique with autopolymerizing acrylic resin, which is known to produce weaker resin than the heat-cured technique; and (2) many patients in the age groups treated by pedodontists and orthodontists do not comply with instructions on the proper storage and care of prostheses. Various approaches to strengthening acrylic resin prostheses have been suggested, which include modifying or reinforcing the resin. The most common reinforcing technique is the use of solid metal forms embedded in the prostheses, although the reported results have been variable and in disagreement. The increase in strength created by the addition of a lingual bar or stainless steel wire was not thought to be clinically significant by one researcher,’ and another concluded that metal reinforcement was ineffective unless at least 50% of the cross-section was occupied by metal.’ Others report that chromium-cobalt strengtheners had a reinforcing action.2,” This study was conducted to determine the effect of the use of commonly available materials to reinforce autopolymerizing acrylic resin.