Aim: Evaluating the influence of adding silicon dioxide nanoparticles (SiO2 Nps) on fracture strength and surface roughness of implant-retained mandibular acrylic overdentures
Materials and methods: A mandibular epoxy resin model was constructed from a completely edentulous mold. Two implants were inserted at the canine areas bilaterally. Experimental overdentures were constructed with metal housings of ball and socket attachments. Overdentures for the SiO2 Nps group were constructed from heat-cured acrylic resin material with the incorporation of 1% silanized SiO2 Nps and overdentures for the control (conventional PMMA) group were constructed from heat-cured acrylic resin material. The fracture strength was measured in newtons (N) by a universal testing machine at a speed of 5 mm/min. The surface roughness of overdentures was measured in micrometers (µm) by using a stylus profilometer.
Results: Regarding fracture strength, the PMMA overdenture base group reinforced with 1% SiO2 Nps had significantly higher fracture strength compared to the control group. On the other hand, the surface roughness of the SiO2 Nps overdenture base group was significantly higher than the control group.
Conclusion: Within the limitations of this study, the incorporation of 1.0 % silanized SiO2 Nps to heat-cured PMMA may significantly increase the fracture strength and surface roughness of the denture base in implant-retained mandibular overdenture.