MECHANICAL-PROPERTIES OF A LIGHT-POLYMERIZING PROVISIONAL RESTORATIVEMATERIAL WITH AND WITHOUT REINFORCEMENT FIBERS

Interim restorations are vulnerable to inadvertent fracture during mas tication. Autopolymerizing acrylic resins have traditionally been sele cted for fabrication of provisional restorations, Triad light-polymeri zing tooth-colored acrylic resin was recently introduced as an alterna tive material for this procedure. This material does not contain methy l methacrylate monomer and permits an increased working time, Heavy oc clusal forces may initiate cracks within these restorations, and propa gation of these cracks may ultimately lead to failure. Various forms o f reinforcement fibers are available and are marketed for strengthenin g dental resins used for provisional restorations, Investigators have demonstrated that the mechanical properties of acrylic resins may be i mproved with the incorporation of reinforcing fibers, but a published evaluation of fiber-reinforced light-polymerizing provisional restorat ive materials is lacking, This investigation recorded and compared two mechanical properties of one light-polymerizing provisional restorati ve material with and without incorporation of vertically and horizonta lly oriented woven, matted, polyethylene fibers. No significant differ ence in modulus of rupture was recorded between groups with and withou t fibers. The mean flexural elastic modulus of the group with the hori zontally oriented fibers was significantly greater than the mean flexu ral elastic modulus of the specimens without incorporated fibers.