title: The effects of disinfectants on dimensional accuracy and surface quality of impression materials and gypsum casts.
abstract: BACKGROUND
  The study aimed to evaluating the effect of disinfecting impression materials on the dimensional accuracy and surface quality of the resulting casts.
  
  
  METHODS
  Impressions of a steel die constructed according to ANSI/ADA specification No.18 were made with each of alginate, addition cured silicone, condensation cured silicone and zinc oxide eugenol paste, and disinfected consequently by each of 0.2% chlorhexidine gluconate, 1% sodium hypochlorite, 2% gluteraldehyde for 5 minutes, and 0.5% sodium hypochlorite for 10 minutes. Dimensions of the disinfected impressions and their resultant casts were measured using a computerized digital caliper, and the dimensional changes were calculated. Reproduction of detail and surface quality of the resultant casts were assessed by grading casts surfaces according to a specific scoring system.
  
  
  RESULTS
  The 0.5% sodium hypochlorite was found to produce the least dimensional changes in all the impression materials. Corsodyl produced the maximum changes in both alginate and zinc-oxide eugenol while addition-cured silicon was most affected by Gluteraldehyde and condensation-cured silicon was most affected by Hexana. The dimensional changes, however, were minimal and clinically insignificant. Addition-cured silicon showed the best surface quality and dimensional stability followed by condensation-cured silicon. Alginate and zinc-oxide eugenol had poorer surface quality and were affected to a higher extent by the disinfection procedures.
  
  
  CONCLUSIONS
  The results were comparable with the standard specifications for dimensional stability. Recommendations were made for the use of 10 minutes immersion in 0.5% sodium hypochlorite as the most appropriate disinfection protocol to the investigated impression materials.
  
  
  BACKGROUND
  Disinfectants; Gypsum casts; Impressions; Alginate; Addition-cured silicone; Sodium hypochlorite.
authors.affiliation: Department of Prosthetic Dentistry, Faculty of Dentistry, University of Jordan, P.O. Box 13455, Amman 11942, Jordan.
authors.forename: Wala M
authors.initials: WM
authors.lastname: Amin
authors.forename: Muna H
authors.initials: MH
authors.lastname: Al-Ali
authors.forename: Sandra K
authors.initials: SK
authors.lastname: Al Tarawneh
authors.forename: Sahar Th
authors.initials: ST
authors.lastname: Taha
authors.forename: Mohamed W
authors.initials: MW
authors.lastname: Saleh
authors.forename: Nadia
authors.initials: N
authors.lastname: Ereifij