Efficacy of various chlorhexidine disinfecting agents on the reduction of bacteria and dimensional stability of alginate impression material

Abstract

      Contaminated dental impression with saliva and blood provide a risk of cross infection for the dentist and dental laboratory staff. Microorganism from oral cavity in facts can survive on the impression surface and can be transferred to the stone castsThe aim of the study: To determine the effect of immersion of Chlorhexidine disinfection procedure on the contamination and dimensional stability of alginate impression materialMaterials and methods: 40 volunteer students were selected from Dental Department in the Collage of Medical and Dental Technologies in Baghdad with age ranged from 18-22 years (20 females and 20 males). The students have been classified into 4 groups each group of 10 students.After taking impression of upper dental arch by alginate, the impressions of the first group were immersed in tap water for 10 minutes (the control group). The second group impressions were immersed in Corsodyl mouthwash )Glaxosmithkline group of companies United Kingdom( (Chlorhexidine digluconate 0.2%)  for 10 minutes. The third group impressions have immersed in )zak DNV Syria( mouthwash (Chlorhexidine digluconate 0.12%)  for 10 minutes. The fourth group impressions were immersed in Almansor mouthwash )Almansor company Iraq Baghdad) (Chlorhexidine digluconate 0.2%)  for 10 minutes.ll these impressions were swabbed and inoculated into blood agar plates, plates were incubated and examined for the bacterial colonies growthsThe second part of the study was to investigate the effects of disinfection solutions (different types of Chlorhexidine) on the dimensional stability of alginate impression material. forty specimens were immersed in  4 different  solutions groups : group 1 immersed for 10 minutes in tap water (control group), group 2 immersed for 10 minutes in Corsodyl mouthwash (Chlorhexidine digluconate 0.2%)  , group 3 immersed for 10 minutes in zak mouthwash (Chlorhexidine digluconate 0.12%) , group 4 immersed for 10 minutes in Almansor mouthwash (Chlorhexidine digluconate 0.2%)Results: the contamination frequency were compared for statistical significance, the alginate (irreversible hydrocolloid) showed contamination in tap water and there was a significant reduction of bacterial growth with Chlorhexidine mouth wash. Corsodyl brand type has superior antibacterial effect over the other two types. There was no significant differences in the dimensional changes test between different types of Chlorhexidine and tap water. Disinfectants techniques by immersion alginate dental impression for 10 minutes caused no significant dimensional change.Conclusion: the use of Chlorhexidine disinfection after taking alginate dental impression is a good measure in reduction of contamination and cross infection and have a minute effect on dimensional stability  and is recommended as step in protecting dentist and dental laboratories teams.Key words: Chlorhexidine, alginate impression, cross infection, dimensional stability