Physical properties of polyamide-12 versus PMMA denture base material.
BIOMED RESEARCH INTERNATIONAL 2014;
2014:150298. [PMID:
24734225 PMCID:
PMC3966424 DOI:
10.1155/2014/150298]
[Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 01/22/2014] [Accepted: 01/22/2014] [Indexed: 11/18/2022]
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 μ m, PMMA 0.28 μ m) 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.
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