Effect of Nano-Zirconia Versus Glass Fibers As Reinforcing Materials for Maxillary Single Dentures on Candidal Growth and Fracture Resistance

Abstract

Polymethyl methacrylate resin is the most commonly used material in construction of dentures. However, one of its most pitfalls is low fracture resistance, hence dentures especially single maxillary dentures are prone to fracture. Thus, assessment of the reinforcement of acrylic resin single denture bases with different materials is the goal of this study. Fourteen patients with edentulous upper arches opposing dentate arches were precisely selected and thoroughly examined to share in this study. Upper single acrylic dentures were constructed and according to the type of reinforcing material; patients were equally divided into two groups Group I: Patients in this group received upper single acrylic dentures reinforced with nano Zirconium oxide powder. Group II: Patients in this group received upper single acrylic dentures reinforced with chopped E- glass fibers. The effect of reinforcing materials on Candida albicans growth was assessed; swabs were collected from the palate of patients and from the dentures fitting surface at insertion and one and three months after insertion. Also, fracture resistance was evaluated six months after denture use by applying bilateral occlusal load using the Universal testing machine on the premolar molar area of the reinforced denture that was supported by acrylic casts made to have stable base during fracture resistance testing. The load was recorded at the first sound of fracture. The results obtained from this study revealed non-significant difference in the effect of both reinforcing materials on Candida albicans growth. Results also showed statistical insignificant difference in the fracture resistance of dentures reinforced by E-glass fibers versus dentures reinforced by nano zirconium oxide under loading.