• acetal resins;
  • gloss;
  • colour changes;
  • sorption;
  • immersion cleansers

doi: 10.1111/j.1741-2358.2012.00657.x

The effect of immersion cleansers on gloss, colour and sorption of acetal denture base material

Objective:  To study the effect of peroxide and hypochlorite cleansers on gloss, colour and sorption of acetal denture resins.

Materials and methods:  Pink acetal and thermoplastic acrylic resins were evaluated. Thirty-five specimens 39 × 39 × 1.8 mm of each resin were prepared. Each group of specimens (n = 7) was then immersed into cleansers for 100 days. Group I immersed in tap water, Group II in Corega Extradent for 5 min, Group III in Corega Extradent for 8 h, Group IV in NitrAdine™ Seniors for 15 min and Group V in NaOCl 5.25%. Gloss, colour and weight measurements were taken initially and after 100 days. Data subjected to two-way anova and Tukey’s test at α = 0.05.

Results:  Acrylic resin showed reductions of glossiness from −5 to −15 and acetal from −0.2 to −6. Colour changes (ΔΕ*) ranged from 2.64 to 7.64 for acrylic and 2.77 to 26.54 for acetal resin. Sorption for acrylic ranged from 11.64 to 17.06 μg/mm3 and 9.18 to 24.79 μg/mm3 for acetal resin. The results of (ΔΕ*) and sorption showed an interaction between denture resins and cleansers.

Conclusions:  The gloss of acetal resin was less affected by water, peroxides and NaOCl 5.25% compared with acrylic resin. Acetal resin showed clinically acceptable (ΔΕ*) whereas acrylic resin unacceptable ones for water and peroxide solutions. The immersion of acetal resin in NaOCl 5.25% showed clinically unacceptable (ΔΕ*) and higher sorption and should be avoided or should be managed with care.