Effect of Zirconium Oxide Nano-Fillers on Dimensional Accuracy of Acrylic Resin Maxillary Complete Dentures: An in vitro study

Introduction: Addition of nanofillers to the denture base material in order to enhance its mechanical properties may contribute to the dimensional accuracy of the processed dentures. Aim: This study was conducted to investigate the effect of zirconium oxide nanofillers addition on the dimensional accuracy of maxillary heat cured acrylic dentures. Materials and Methods: Thirty six identical maxillary waxed up dentures were constructed, divided into two equal groups(n=18), control group processed into conventional heat cured acrylic resin dentures and test group processed into 5% zirconium oxide nanofiller reinforced heat cured acrylic resin dentures. Teeth movements were estimated linearly using digital software after processing and vertically using digital caliper before and after processing. Changes in denture adaptation were measured immediately after processing and after seven days hydration in distilled water using digital software. Results: After processing, both groups showed increased Vertical dimension of occlusion with less increase with the test group. Both groups showed changes in teeth position with non-significant difference. Test group showed more tendency to inward tooth movement. Test group showed significant more denture adaptation after processing. However, denture hydration caused decrease in denture adaptation in the test group while causing enhancement in denture adaptation with the control group. Conclusion: Zirconium oxide nanofillers reinforcement showed nearly comparable results of dimensional accuracy to the conventional dentures with negative results on hydration.