Firas Abd Kati Al-Shammari*1, Akhlas Zeid Abood, Ihab Nafea Yaseen
Acrylic resins are commonly used for fabrication of removable dentures. The aim of this study was to assess the effect of aging in water on tensile strength of acrylic after manipulation with chemical and mechanical surface treatments. 160 specimens were prepared from heat-cured resins and divided into 4 groups according to time of immersion in water. Acrylic samples were cut into two halves and then repaired with heat-cured acrylic resin. All acrylic samples were tested under tensile loads till fracture. The tensile strength was affected by water aging and surface treatments used. The acrylic samples reinforced by metal wire had the maximum tensile strength for all groups. In addition, the acetone group created a higher tensile strength than monomer and untreated group (P<0.001). Furthermore, the application of a liquid monomer increased significantly the tensile strength as compared to untreated group (P<0.001). Moreover, There were a highly significant differences between repaired groups (P<0.001). For water aging, there were a highly significant differences among all groups (P<0.001). The tensile strength of repaired samples which immersed in water for one day was greater than that of samples immersed for 7 days, two and 4 weeks. The present study concluded that the tensile strength of acrylic resin had been significantly affected by water aging and surface treatments used. The tensile strength of repaired acrylic resin had been significantly reduced when samples immersed in water for long time. It is recommended for the patients to repair their fractured dentures immediately.
Keyword: Tensile strength; Acrylic; Water storage; Repair hemorrhage