Physical Properties of Polyamide-12 versus PMMA Denture Base Material

الملخص EN

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

Significance.

PA exhibited a higher susceptibility to discoloration than PMMA.

Neither surface roughness nor elasticity of PA was altered by artificial aging.