A New Approach to Cure and Reinforce Cold-Cured Acrylics

Abstract

Purpose The low degree of polymerization of coldcured acrylics has resulted in inferior mechanical properties and fracture vulnerability in orthodontics removable appliances. Methods In this study, the effect of reinforcement by various concentrations of chopped E-glass fibers (0%, 1%, 2%, 3% and 5% by weight of resin powder) and post-curing microwave irradiation (800 W for 3 min) on the flexural strength of cold-cured acrylics was evaluated at various storage conditions (at room temperature for 1 day and 7 days; at water storage for 7, 14 and 30 days). Results The data was analyzed by using 1-way and 2-way ANOVA, and a Tukey post hoc test (α = .05). The specimens with chopped E-glass fibers treated with post-curing microwave irradiation significantly increased the flexural strength of cold-cured PMMA. The optimal concentration might be 2% fibers under irradiation. Conclusions The exhibited reinforcement effect lasted in a consistent trend for 14 days in water storage. A new fiber-acrylic mixing method was also developed.

Designing an antibacterial acrylic resin using the cosolvent method —Effect of ethanol on the optical and mechanical properties of a cold-cure acrylic resin

“…In the absence of ethanol (0E), the bending strength was nearly 100 MPa and the elastic modulus was about 2.7 GPa, which are comparable to previously reported values 11,12) . However, both the bending strength and the elastic modulus significantly decreased with an increasing E/M ratio (p<0.05), with the values for both measurements decreasing by less than 10% in 0.25E specimens, compared with up to 80% in 1E specimens.…”

Flexural Strength and Hardness of Filler-Reinforced PMMA Targeted for Denture Base Application

“…Each of the three reinforced PMMA groups (n = 10 each group) were further sub-divided into four subgroups according to the concentration of filler used: 1.5%, 3%, 5%, and 7%) (Table 2). All the specimens were prepared according to the manufacturer's instructions and tested per ISO specifications [38,39], according to previous studies [5,6,18,40]. Pilot studies determined that the percentages of the silanized fillers used should be 1.5 wt.%, 3 wt.%, 5 wt.%, and 7 wt.%.…”

“…The major challenges that dental clinicians traditionally encounter in prosthetics and restorations pertain to the lack of biocompatibility of materials, the difficulty in achieving a natural appearance, and the inability to develop a material that can withstand exposure to the harsh oral environment [ 1 , 3 , 4 ]. PMMA has been a preferred choice in the production of denture bases since its introduction in 1930s [ 5 , 6 ]. While dental implants are increasingly being used as substitutes for natural teeth in both partially dentate and edentulous patients, PMMA remains the preferred choice for denture base construction [ 7 ].…”

Biological and Chemo-Physical Features of Denture Resins

“…Mica seemed to give less flexural strength with high microhardness to dentures. So et al [ 48 ] evaluated the effect of reinforcement by various concentrations of chopped E-glass fibers (0%, 1%, 2%, 3% and 5% by weight of resin powder) and post-curing microwave irradiation (800 W for 3 min) on the flexural strength of cold-cured acrylics. According to them, at room temperature and humidity for 1 day, the group with 3% and 5% fiber reinforcements obtained significant results compared to test group.…”

“…Monteiro et al [ 49 ] showed how antimicrobial denture base resins containing silver colloidal nanoparticles present a better silver distribution and dispersion at a lower silver ratio. So et al [ 48 ] concluded that glass fiber and post-curing microwaving improve the flexural strength in cold-cured PMMA, but it could be influenced by the water storage time of the resin. They suggest a new mixing method called the “sprinkle method” in the fabrication of orthodontic appliances.…”