The Impact of Polymerization Technique and Glass-Fiber Reinforcement on the Flexural Properties of Denture Base Resin Material

Abstract

Objective Different polymerization and reinforcement techniques have been tested to enhance the mechanical characteristics of denture base acrylic resins. The goal of the present study was to evaluate the influence of autoclave polymerization techniques with glass fiber reinforcement on the flexural strength and elastic modulus of polymethyl methacrylate denture base resins. Materials and Methods Ninety specimens were fabricated from heat-polymerized acrylic resin and randomly distributed depending on the polymerization technique into three groups (n = 30): water bath polymerization, short-cycle autoclave polymerization, and long-cycle autoclave polymerization. Each group was further divided into three subgroups (n = 10) based on the concentration of glass fiber 0, 2.5, and 5wt%. The flexural strength and elastic modulus were investigated using a universal testing machine. One-way ANOVA and Tukey's post hoc test were performed to analyze the results (α = 0.05). ResultsThe flexural strength and elastic modulus values were significantly higher in 5wt% glass fiber reinforced long-cycle autoclave group in comparison with the other test groups (p < 0.05). Conclusions The long-cycle autoclave polymerization technique with the glass fiber reinforcement significantly increased the flexural strength and elastic modulus of the denture base resin material. AbstractKeywords ► autoclave ► water bath ► polymerization ► glass fiber ► denture base

Prosthodontic Applications of Polymethyl Methacrylate (PMMA): An Update

“…Therefore, good mechanical properties are required for the functional performance of denture base materials (biofunctionality). Considering the significance of the mechanical properties, several modifications have been reported for various mechanical properties of PMMA, including its flexural strength [ 14 , 30 , 33 , 68 , 134 , 135 , 136 ], impact strength [ 14 , 137 , 138 , 139 , 140 ], fracture toughness [ 141 , 142 , 143 ], and surface hardness [ 67 , 98 , 141 , 144 , 145 ]. The flexural strength (also known as the modulus of rupture or transverse strength) is assessed using a 3-point bending test according to the guidelines of ISO 20795-1 [ 81 ].…”

“…Ideally, the denture base should have a high flexural strength to bear the complex forces of mastication without permanent deformation or fracture [ 9 ]. A number of studies have investigated [ 14 , 30 , 33 , 68 , 134 , 135 , 136 ] flexural strength using various methods and types of PMMA. Barbrosa et al [ 146 ] reported good flexural strength for heat-cured, cold-cured, and microwave-cured PMMA (92.84 ± 4.73, 84.40 ± 1.68, and 109.63 ± 5.31 MPa, respectively).…”

“…To improve the properties of PMMA materials, a variety of fibers have been added and extensively characterized ( Table 6 ). Several studies [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ] have reported the improvement of various properties of fiber-reinforced PMMA. The characteristic reinforcement benefits are obtained due to the greater length of the fibers compared to the cross-sectional diameter.…”

“…Although there are a number of concerns associated with using PMMA, such as the fracture of dentures due to water sorption and poor impact and flexural strength, the ongoing research has introduced a variety of modifications to overcome and further improve its properties (such as its conductivity, water sorption, solubility, impact and flexural strengths). For example, several studies reported the improvement of PMMA materials while reinforced using a variety of fibers [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ], nanoparticles [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ], and nanotubes [ 38 , 39 , 40 , 41 , 42 ]. Similarly, PMMA-based biocomposites with the addition of epoxy resins, polyamide, or butadiene styrene have been reported to improve the impact strength of PMMA [ 43 ].…”

Effect of silicon dioxide nanoparticles on the flexural strength of heat-polymerized acrylic denture base material: A systematic review and meta-analysis

“…Heat-polymerized acrylic resin is commonly used to fabricate definitive complete and partial removable dental prostheses ( Polychronakis et al, n.d. ). It has the features of a natural intra-oral appearance; biocompatibility; simple processing, finishing, and polishing techniques; and cost efficiency ( Al-Thobity, 2020 , Gad et al, 2019b ). However, it has low flexural strength and toughness.…”