title: Colour stability of relined dentures after chemical disinfection. A randomised clinical trial.
abstract: BACKGROUND
  This randomised clinical study evaluated the effect of chemical disinfection with sodium perborate or chlorhexidine on the colour stability of a hard chairside reline resin during six months.
  
  
  METHODS
  Hard chairside reline resin (Tokuyama Rebase Fast II) was used to reline complete dentures. After baseline colour measurements, the patients were randomly divided into 3 groups (n = 15) and allocation was concealed with the use of the BioStat program. The dentures were cleansed according to three methods: CG (control group)--brushing with coconut soap and soft toothbrush, PG (Perborate group)--brushing according to previous methods and disinfection with warmed sodium perborate solution (Corega Tabs) for 5 min, once a day for 6 months and ChxG (Chlorhexidine Group)--brushing according to CG and disinfection with chlorhexidine digluconate 2% for 5min once a day for 6 months. The data of ΔE*, ΔL*, Δa* and Δb* were analysed by 2-way repeated-measures ANOVAs and Tukey tests (α = 0.05).
  
  
  RESULTS
  There were significant differences amongst groups for ΔL, Δa and Δb. The time had a significant effect on ΔE and ΔL, for all groups evaluated.
  
  
  CONCLUSIONS
  Changes in some colour parameters (ΔL, Δa and Δb) of the reline resin Tokuyama Rebase were observed when the dentures were disinfected by perborate and chlorhexidine digluconate 2% solutions. The colour stability of was also influenced by time, regardless of disinfection or nondisinfection.
  
  
  CONCLUSIONS
  Colour stability of the denture materials is one variable to be considered when choosing disinfection methods. The data in this study will be useful to clinicians when they are selecting disinfectant solutions for disinfection of relined denture.
authors: Department of Dental Materials and Prosthodontics, Araraquara Dental School, UNESP - Univ Estadual Paulista, Rua Humaita, 1680 CEP 14801-903 Araraquara, São Paulo, Brazil.
authors: Eduardo Buozi
authors: EB
authors: Moffa
authors: Eunice Teresinha
authors: ET
authors: Giampaolo
authors: Fernanda Emiko
authors: FE
authors: Izumida
authors: Ana Cláudia
authors: AC
authors: Pavarina
authors: Ana Lúcia
authors: AL
authors: Machado
authors: Carlos Eduardo
authors: CE
authors: Vergani
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001881:Borates; D002710:Chlorhexidine; D003116:Color / Q000592:standards; D003124:Colorimetry / Q000379:methods; D019551:Dental Disinfectants; D003820:Denture Cleansers; D003823:Denture Rebasing; D003827:Denture, Complete, Upper; D004203:Disinfection / Q000379:methods*; D006801:Humans; D008689:Methacrylates; D008875:Middle Aged; D017797:Prosthesis Coloring; D013053:Spectrophotometry; D018709:Statistics, Nonparametric; D013997:Time Factors
chemical_list: D001881:Borates; D019551:Dental Disinfectants; D003820:Denture Cleansers; D008689:Methacrylates; C437925:Tokuso rebase normal-set; D002710:Chlorhexidine; C027707:sodium perborate