ABSTRACT
Objectives: Investigate the impact of adding zirconia dioxide nanoparticles (ZrO2 NPs) on the surface roughness and fracture strength of implant-retained acrylic mandibular overdentures.
Materials and method: An epoxy resin model of a completely edentulous mandibular arch was poured. Two implants were inserted in the canine regions. Two balls and a socket attachment were attached to these implants. Twelve casts were duplicated from the implant epoxy model and divided into two groups. Group I (Control Group): overdentures were made from heat-cured polymethyl methacrylate (PMMA). Group II (Test Group): overdentures were made from heat-cured PMMA modified by 3% silanized ZrO2 NPs. The surface roughness (Ra) was measured by a contact stylus profilometer in micrometers (μm). A universal testing machine was used to measure fracture strength.
Results: The results of this study revealed a significant increase in the surface roughness of the tested group, while the results demonstrated insignificant differences between the two groups in fracture strength.
Conclusion: The addition of 3% silanized ZrO2 NPs to implant-retained acrylic overdentures enhances the mechanical properties of the denture base; however, the thickness of the denture base is to be considered.