Physical Properties of Polyamide-12 versus PMMA Denture Base Material

Abstract

Objectives. Polyamide-12 (PA) is a flexible material suited for denture bases and clasping. This study investigated its potential aging effects with a focus on surface roughness, color stability, and elasticity. Methods. PA specimens (Valplast) of 40 × 10 × 2 mm and equally measuring PMMA specimens (Palapress) as control were fabricated. Color changes after storage in air, water, coffee, and red wine (n = 10) were measured using the CIE L*a*b* color specification. Elasticity after thermocycling (1000, 3000, and 7000 cycles, n = 15) was measured by three-point bending testing. Mean surface roughness (Ra) was determined after storage in the liquids mentioned above and thermocycling (n = 10). Results. Tukey's HSD test (P < 0.05) revealed statistically significant color changes of PA in red wine (ΔE = 4.27 after 12 days, ΔE = 6.90 after 12 days) and coffee (ΔE = 3.93 after 36 days) but no color changes in PMMA. Elastic modulus of PA was 845 MPa and not affected by thermocycling (Tukey's HSD test, P > 0.81). Dry specimens showed significantly decreased elasticity (P < 0.001). Mean surface roughness (PA 0.20 μm, PMMA 0.28 μm) did not change significantly after thermocycling or storage (Mann-Whitney U-test, 0.16 < P < 0.65). Significance. PA exhibited a higher susceptibility to discoloration than PMMA. Neither surface roughness nor elasticity of PA was altered by artificial aging.

Effect of fiber content on flexural properties of glass fiber-reinforced polyamide-6 prepared by injection molding

“…They are considered to be superior to conventional RPDs with metal clasps in terms of esthetics; however, the use of NMCDs made from thermoplastics, especially polyamide, may seriously affect some tissues because of the low rigidity of thermoplastics. Several types of polyamide are commercially available 4,18) . Polyamides are semicrystalline polymers whose repeating units are characterized by the amide group.…”

“…Removable partial dentures (RPDs) using resin-clasp retentive parts are defined as non-metal clasp dentures (NMCDs), and are often much more esthetically pleasing than conventional RPDs with metal clasps 2) . Generally, thermoplastic resins such as polyamide, polyester and polycarbonate have been used as NMCDs that can be injection-molded in one piece including clasps, minor and major connectors, and denture bases [2][3][4] . Several types of polyamides are most commonly used, having the longest history among the thermoplastic resins used for NMCDs 2) .…”

“…Several types of polyamides are most commonly used, having the longest history among the thermoplastic resins used for NMCDs 2) . Several studies have evaluated the properties of polyamide denture base materials, such as their flexural properties 1,5,6) , water sorption 1,7,8) , color stability 1,4,7) , bond strength to acrylic resins 9,10) , dimensional accuracy 11) , and surface roughness 4,12) . According to the results of these studies, polyamides were thought to be an alternative to the conventional acrylic resins due to their esthetic and functional characteristics and physical properties such as thermo-injectability, high impact strength and flexibility.…”

“Comparative Evaluation Of Biofilm Development Of Candida Albicans On Abraded Surfaces Of Heat Cure PMMA And Flexi Denture Material”:An In Vitro Study

“…The surface roughness play a major role in microbiological attachment, more rougher the surface more the candidal count. 7 Surface roughness and surface free energy (SFE) may contribute to the positively correlated rate of microbial colonization and plaque maturation on surfaces. 8 The result of the microbiological study have showed that the finishing and polishing technique that show lower surface roughness value have less number of Candidal cells attachment.…”

Effect of soft drink towards heat cured acrylic resin denture base surface roughness

“…Micro cracks produced by direct contact with acidic fluids in a certain concentration and intensity level. 5,6 Surface roughness is a condition where a surface condition of one object is wavy and irregular. 7 The condition of the surface of heat cured acrylic resin denture base material inside the oral cavity will affect plaque buildup that will increase the amount of Candida albicans colony that can cause denture stomatitis.…”