The Reinforcement Effect of Nano-Zirconia on the Transverse Strength of Repaired Acrylic Denture Base

Abstract

Objective. The aim of this study was to evaluate the effect of incorporation of glass fiber, zirconia, and nano-zirconia on the transverse strength of repaired denture base. Materials and Methods. Eighty specimens of heat polymerized acrylic resin were prepared and randomly divided into eight groups (n = 10): one intact group (control) and seven repaired groups. One group was repaired with autopolymerized resin while the other six groups were repaired using autopolymerized resin reinforced with 2 wt% or 5 wt% glass fiber, zirconia, or nano-zirconia particles. A three-point bending test was used to measure the transverse strength. The results were analyzed using SPSS and repeated measure ANOVA and post hoc least significance (LSD) test (P ≤ 0.05). Results. Among repaired groups it was found that autopolymerized resin reinforced with 2 or 5 wt% nano-zirconia showed the highest transverse strength (P ≤ 0.05). Repairs with autopolymerized acrylic resin reinforced with 5 wt% zirconia showed the lowest transverse strength value. There was no significant difference between the groups repaired with repair resin without reinforcement, 2 wt% zirconia, and glass fiber reinforced resin. Conclusion. Reinforcing of repair material with nano-zirconia may significantly improve the transverse strength of some fractured denture base polymers.

The effects of adding various ratios of zirconium oxide nanoparticles to poly(methyl methacrylate) on physical and mechanical properties

“…Studies show that administering an appropriate additive to PMMA can improve the propZirconium oxide (ZrO 2 ) is a metal oxide that possesses several advantages such as good mechanical strength, fracture toughness, hardness, wear and chemical resistance, and good thermal stability, thus making it beneficial for use in dental materials such as denture base reinforcement (4,8,11,12). ZrO 2 is a polymorphic material, is available in three stable phases: monoclinic, tetragonal, and cubic.…”

“…Nanotechnology has recently been used in the prosthodontic field for material enhancement purposes (9,12), which has been emphasized in the study of nanomaterials for improving the mechanical properties of PMMA. Nanofillers such as nanoclays, nanotubes, nanofibers, and nanoparticles are the current alternatives for improving the mechanical properties of PMMA (2).…”

“…Nanofillers such as nanoclays, nanotubes, nanofibers, and nanoparticles are the current alternatives for improving the mechanical properties of PMMA (2). The effect of nanoparticles on the mechanical properties of PMMA depends on several factors including polymerparticle interface, particle size, fabrication method, and particle dispersion in the PMMA matrix (11,12). One of the most common nanoparticle fillers in use is ZrO 2 .…”

“…This bioceramic filler has high flexural strength and fracture toughness due to transformation toughening (7). Incorporating ZrO 2 into PMMA has been suggested to improve PMMA properties (4,12).…”

“…Nanoparticle aggregates disrupt the mechanical properties and reduce the optic properties of polymer-based material. Good adhesion and dispersion homogeneity of nano-ZrO 2 with the resin matrix and the small nanoparticle size improve the transverse strength of PMMA (12,17). Therefore, organic solvents or monomer (silane coupling agent) could be used to disperse nanoparticles in the matrix (2,18).…”