The impact of surface pre-reacted glass-ionomer nanoparticles on ion dynamics and the physio-mechanical properties of denture base resin

Abstract

OBJECTIVE: this study evaluated the effects of incorporating 5wt% and 10wt% surface pre-reacted glass-ionomer S-PRG nanoparticles into a polymethylmethacrylate (PMMA) resin on multiple-ion exchange rates following recharge with an S-PRG solution, flexural strength, surface roughness, and hardness. METHODOLOGY: In total, 72 disc-shaped and 32 rectangular specimens were fabricated from PMMA resin containing 0, 5, and 10% S-PRG nanoparticles, and 20% S-PRG microparticles by weight. In total, six-disc specimens per group were tested for surface roughness and hardness using a contact profilometer and the Vickers hardness test, respectively. The remaining discs were immersed in 11 ml of deionized water for 24 hours, followed by an analysis of their aluminum, boron, sodium, silicate, strontium, and fluoride concentrations. They were then recharged with a 10% S-PRG solution for 24 hours, alternating with deionized water for five cycles, before their ion levels were reanalyzed. Rectangular specimens underwent flexural strength testing via the three-point bending method. Data were analyzed using two-way repeated-measures analysis of variance with a significance level of p<0.05. RESULTS: PMMA resin modified with S-PRG nanoparticles released all ions except aluminum. The 10wt% nanoparticle group showed significantly higher ion release than the 5wt% nanoparticle and control groups. While the initial ion release from the 10wt% nanoparticle was comparable to the 20wt% microparticle, recharge resulted in slower ion release from nanoparticles. Incorporating S-PRG nanoparticles altered the surface characteristics and flexural strength of the resin (which remained within international standards). CONCLUSION: Incorporating 5 and 10wt% S-PRG nanoparticles into PMMA resin facilitated the release of boron, silicate, strontium, sodium, and fluoride ions, but not of aluminum ones following recharge with an S-PRG solution and maintained compliance with standards. The 10wt% nanoparticles achieved a balance between enhanced ion release and the physio-mechanical properties required for denture base resins.