Influence of High‐Pressure Polymerization on Mechanical Properties of Denture Base Resins

<jats:title>Abstract</jats:title><jats:sec><jats:title>Purpose</jats:title><jats:p>The purpose of this study was to study the influence of high‐pressure (HP) polymerization on the mechanical properties of denture base PMMA resins compared with conventional thermopolymerization and PMMA discs for digital dentures.</jats:p></jats:sec><jats:sec><jats:title>Materials and Methods</jats:title><jats:p>Three groups of blocks were prepared: Probase Hot (Ivoclar Vivadent, Lichtenstein) conventionally heat polymerized at 100°C, Probase Hot heat polymerized at 100°C under HP (200 MPa) and Ivobase CAD (Ivoclar Vivadent, Lichtenstein). Samples for mechanical/physical (n = 30) and samples for viscoelastic (n = 10) characterizations were cut from the blocks. Flexural strength (σ<jats:sub>f</jats:sub>), elastic modulus (E<jats:sub>f</jats:sub>), hardness, density (ρ), flexural deformation at maximal flexural stress, flexural load energy (U<jats:sub>r</jats:sub>) and viscoelastic properties (E’, E’’, Tanδ, T<jats:sub>g</jats:sub>) were analyzed using one‐way ANOVA (α = 0.05), Scheffé multiple means comparisons (α = 0.05) and Weibull statistics (for σ<jats:sub>f</jats:sub>). SEM images of the fractured surfaces were obtained.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>E<jats:sub>f</jats:sub>, E’, E’’ and density of HP polymerized Probase hot were significantly higher than conventional heat polymerized Probase Hot, whereas T<jats:sub>g</jats:sub> was significantly lower and σ<jats:sub>f</jats:sub>, Tanδ, hardness, flexural deformation at maximal flexural stress, U<jats:sub>r</jats:sub> were not significantly different. The highest values for σ<jats:sub>f</jats:sub>, flexural deformation at maximal flexural stress, U<jats:sub>r</jats:sub> and Weibull modulus were obtained with Ivobase CAD.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>HP polymerization does not significantly increase the mechanical properties of denture base resins.</jats:p></jats:sec>