title: The effect of immersion cleansers on gloss, colour and sorption of acetal denture base material.
abstract: OBJECTIVE
  To study the effect of peroxide and hypochlorite cleansers on gloss, colour and sorption of acetal denture resins.
  
  
  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/mm(3) and 9.18 to 24.79 μg/mm(3) 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.
authors.affiliation: Department of Prosthodontics, Dental School, University of Athens, Athens, Greece. grepolyz@dent.uoa.gr
authors.forename: Gregory
authors.initials: G
authors.lastname: Polyzois
authors.forename: Artemis
authors.initials: A
authors.lastname: Niarchou
authors.forename: Polyxeni
authors.initials: P
authors.lastname: Ntala
authors.forename: Antonis
authors.initials: A
authors.lastname: Pantopoulos
authors.forename: Mary
authors.initials: M
authors.lastname: Frangou
mesh_terms: D000042:Absorption; D000327:Adsorption; D003116:Color; D003764:Dental Materials / Q000737:chemistry*; D003819:Denture Bases; D003820:Denture Cleansers / Q000737:chemistry*; D006801:Humans; D007101:Immersion; D008422:Materials Testing; D010545:Peroxides / Q000737:chemistry; D019904:Polymethyl Methacrylate / Q000737:chemistry; D012117:Resins, Synthetic / Q000737:chemistry*; D012973:Sodium Hypochlorite / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D003764:Dental Materials; D003820:Denture Cleansers; D010545:Peroxides; D012117:Resins, Synthetic; C438105:acetalic resin, Acetal-Dental; C540407:corega tabs; D014867:Water; D019904:Polymethyl Methacrylate; D012973:Sodium Hypochlorite