Influence of various metal oxides on mechanical and physical properties of heat-cured polymethyl methacrylate denture base resins

Abstract

PURPOSETo evaluate the effect of various metal oxides on impact strength (IS), fracture toughness (FT), water sorption (WSP) and solubility (WSL) of heat-cured acrylic resin.MATERIALS AND METHODSFifty acrylic resin specimens were fabricated for each test and divided into five groups. Group 1 was the control group and Group 2, 3, 4 and 5 (test groups) included a mixture of 1% TiO2 and 1% ZrO2, 2% Al2O3, 2% TiO2, and 2% ZrO2 by volume, respectively. Rectangular unnotched specimens (50 mm × 6.0 mm × 4.0 mm) were fabricated and droptower impact testing machine was used to determine IS. For FT, compact test specimens were fabricated and tests were done with a universal testing machine with a cross-head speed of 5 mm/min. For WSP and WSL, discshaped specimens were fabricated and tests were performed in accordance to ISO 1567. ANOVA and Kruskal-Wallis tests were used for statistical analyses.RESULTSIS and FT values were significantly higher and WSP and WSL values were significantly lower in test groups than in control group (P<.05). Group 5 had significantly higher IS and FT values and significantly lower WSP values than other groups (P<.05) and provided 40% and 30% increase in IS and FT, respectively, compared to control group. Significantly lower WSL values were detected for Group 2 and 5 (P<.05).CONCLUSIONModification of heat-cured acrylic resin with metal oxides, especially with ZrO2, may be useful in preventing denture fractures and undesirable physical changes resulting from oral fluids clinically.

PMMA denture base material enhancement: a review of fiber, filler, and nanofiller addition

“…25,[30][31][32][33] In addition, reinforcing PMMA with aluminum increased the flexural strength, impact strength, tensile strength, compressive strength, and surface hardness of the resin. 26,30,32,34 Warpage also decreased significantly after addition of aluminum to PMMA. On the other hand, some studies found that adding aluminum decreases both the impact and tensile strength of PMMA.…”

“…Consequently, better food sensation and healthier oral mucosa were expected by adding metal fillers to denture base resin. [25][26][27] Recently, the incorporation of nanofillers (Table 2) has been suggested to improve PMMA properties. The high surface area, fine size, and homogenous distribution of nanofillers improved the thermal properties of PMMA and increased its thermal stability compared with pure PMMA.…”

“…The high surface area, fine size, and homogenous distribution of nanofillers improved the thermal properties of PMMA and increased its thermal stability compared with pure PMMA. [26][27][28] The properties of resin reinforced by nanofillers depend on the size, shape, type, and concentration of the added particles. 28 …”

“…25,37 Surface roughness and water sorption were not significantly changed with aluminum-reinforced denture resin. 31,35 However, one study found a significant decrease in water sorption and solubility after addition of Al 2 O 3 , 26 and an increase in water sorption was found by another study. 31 Safi 28 concluded that adding Al 2 O 3 nanoparticles (NPs) to PMMA increases its thermal stability compared with pure PMMA.…”

Influence of incorporation of ZrO₂ nanoparticles on the repair strength of polymethyl methacrylate denture bases

“…[18][19][20][21] Zirconia (ZrO 2 ) is a metal oxide that has been widely used because it possesses high mechanical strength, good surface properties, and good biocompatibility and biological properties, thus making it a beneficial material for use in dental materials, such as reinforcement of denture bases and repair. [22][23][24][25] The incorporation of zirconia nanoparticles (nano-ZrO 2 ) into PMMA has been suggested to improve PMMA properties. 26,27 The addition of nano-ZrO 2 to PMMA significantly improves flexural strength and impact strength.…”