Effect of Disinfection on Surface Properties of a Nylon Material

Nylon is chosen in certain clinical cases as denture base material but the effect of disinfection methods on its properties is unclear. The purpose of this study was to determine the influence of disinfection methods on color, gloss and 3-D topography of nylon denture base material in comparison to heat polymerized.

Method:

Sixty disks were made from nylon (Valplast) and heat-polymerized acrylic denture base material (Paladon 65). Ten specimens from each material were immersed in water (control), Val-Clean (peroxide cleanser) and Corega Extradent plus 2 min at 450W microwaving for a period simulating 30 days of daily disinfection. Color, gloss and 3-D topographic parameters (Sa, Sdr) were measured before and after disinfection cycles, using a colorimeter, a gloss meter and an interferometric profilometer. Mann-Whitney, Kruskal-Wallis, unpaired t-tests and regression analysis were used to analyze the data at α= .05 level of significance.

Result:

The results showed significant differences between the two materials at baseline, in primary color parameters L* and b* (P<.001), gloss (P<.0001) and roughness (P<.0001). After disinfection, ΔΕ* was greater in Valplast than in Paladon 65 (P<.05) with no differences among disinfection methods and control (P>.05). Gloss of both materials was decreased significantly within the Corega Extradent plus microwave irradiation (P<.05), but not within Val-clean (P>.05). Roughness was increased only for Paladon 65 and only within Corega Extradent plus microwaving (P<.05).

Conclusion:

Valplast was found to have a significantly lower gloss and a higher roughness than Paladon 65 at baseline. Disinfection changed significantly the color of Valplast with no differences among disinfection methods and control. Gloss and surface roughness was affected only by Corega Extradent plus microwave irradiation.