title: A self-disinfecting irreversible hydrocolloid impression material mixed with povidone iodine powder.
abstract: OBJECTIVE
  The aim was to evaluate the effect of adding povidone (PVP) iodine powder with different concentrations to irreversible hydrocolloid on both microbiological and dimensional stability.
  
  
  METHODS
  Regular set of (alginate) irreversible hydrocolloid was selected as control group. PVP-iodine powder was mixed with the alginate powder at concentrations of 1, 5, 10, 15, and 20% by weight (test groups). All specimens were tested for their antimicrobial effect againstStreptococcus mutansandStaphylococcus aureusas well as dimensional stability.
  
  
  RESULTS
  The results of test groups showed that concentrations 1, 5, and 10, weight % had little effect againstS. mutansandS. aureusmicroorganisms. While concentrations 15 and 20 weight % had demonstrated greater effect on microbial growth. The mean of dimensional stability in mm of modified alginate with PVP-iodine at 15 and 20 weight % was -0.119 ± 0.255 and -0.035 ± 0.074, respectively. While the mean dimensional stability in mm of unmodified alginate was -0.112 ± 0.176. The results of dimensional stability showed that 15 and 20 concentrations of test groups adversely affect the dimensional stability. The adverse effect was noticed to be significant in concentration 20%, where as it was nonsignificant in 15% concentration.
  
  
  CONCLUSIONS
  Modified alginate impression material with 15 weight % PVP-iodine powered give the material, a self-disinfected properties with less deteriorating effect on dimensional stability.
authors.affiliation: Removable Prosthodontics Department, Al-Farabi Colleges of Dentistery and Nursing, Jeddah, KSA.
authors.forename: Hussien Abdalfatah
authors.initials: HA
authors.lastname: Ismail
authors.affiliation: Department of Medical Microbiology and Parasitology, Faculty of Medicine, King Abdul Aziz University, Jeddah, KSA.
authors.forename: Hani
authors.initials: H
authors.lastname: Asfour
authors.affiliation: Removable Prosthodontics Department, Al-Farabi Colleges of Dentistery and Nursing, Jeddah, KSA.
authors.forename: Souaad Abdulelah
authors.initials: SA
authors.lastname: Shikho
keywords: Alginate; disinfection; povidone iodine