The Effect of Two Different E Glass Fiber Reinforcements on Mechanical Properties of Polymethyl Metacrylate Denture Base Resins

Denture base polymers were reinforced with various types of fibers, such as glass, carbon/graphite and ultrahigh-modulus polyethylene fibers. These procedures were performed to take advantage of the good esthetic qualities of glass fibers and good bonding of glass fibers to polymers via silane coupling agents. The most common type of glass used in fiber production is the so-called E glass (electrical glass). This study investigated the effect of chopped fibers with two different silane coupling agents on the strength of denture base polymethyl metacrylate resins. E Glass fibers coupled either with Silan 1 (silan + epoxy resin) or Silan 2 (silan + polyester resin) were used to reinforce denture base polymethyl metacrylate resin. Specimens were produced by two different methods. In the first group, the fibers were wetted with a mixture of polymer powder and monomer liquid and in the second group the fibers were soaked in the polymer liquid for 15 minutes and then blended with PMA polymers. All samples were heat cured. Control group specimens were not fiber reinforced. Half of the prepared specimens were stored in distilled water at 37°C for 48 hours. The others were tested immediately. Transverse strength of all specimens was evaluated by a 3 point bending test. No significant difference was found between the wetted and immediately tested specimens (p=0.755). When all specimens were compared for transfer stength there was statistically significant difference between the wetted and unwetted specimens (p=0). When silanated and control specimens were compared the ones processed with Silan 2 (silan + polyester resin) showed the lowest transfer strenght values