Chlorine Dioxide Spray Disinfection Of Alginate Impression

Objective: The study evaluated the effect of disinfecting on alginate impressions by chlorine dioxide, provide a feasible basis to clinical procedure.Materials and methods:This study includes two parts .Part I :The Stability Measurement of Chlorine Dioxide Solution. Five-step iodometry was. used to determine the concentration of chlorine dioxide, and UV-spectrophotometry was applied to detect the stability of raw solution of chlorine dioxide and the degrade rate of 500mg/L before-after activated chlorine dioxide solution. Statistical comparisons were calculated using SPSS10.0 .Part II :The effect of spraying disinfecting alginate impression by chlorine dioxide. 1. Specimen's collection: The powder of alginate impression ,rubber bown,spatula and trays were disinfected,impressions were made at room temperature. 216 maxillary impressions were collected at oral medical hospital from March to December,2006.2.Grouping:The specimens were divided into 8 groups such as 300mg/L,500mg/L,550mg/L,700mg/L,900mg/L,1000mg/L chlorine dioxide, 20000mg/L glutaraldehyde and 0.1% sodium hypochlorite. Put 550mg/L chlorine dioxide in hermetic condition and exposed to air ,the rest are in hermetic condition.24 specimens in each group.include 18 water flushed specimens of disinfecting deal;in 6 specimens of positive control, 3 specimens were use water flush ,3 disuse;3 specimens of negative control. Calculate the effect of water flush, appreciate bacterial type. 3. Disinfecting:This study apply same type spray bottles, the distance from bottle to impression is 20cm, spray 1 time in a second ,continuous 10 times. Keeping the same pressure to make sure uniform disinfectant was covered on the surface of impression. The impressions were treated with 10min,20min,30min,then mingled with 5ml neutralizer 10min and 5ml stroke-physiological saline solution,vibrated for 80 times to mix bacteria, 1ml diluted mixture liquid were planted on ster culture capsule and incubate. Colony forming units(CFU) were countered and antibacterial effects were analyzed. According to the disinfecting experimental standard, antibacterial effects up to 99.99% were qualified.Results: 1 .Over a half-year period ,non-activited raw solution of chlorine dioxide degraded by 2.01% at 4℃and by 2.65% at 25℃,as shown by comparative measurements.the result indicated that temperature was significant(P<0.01).2.At room temperature, 500mg/L activated chlorine dioxide solution degraded by 8.56% at 12 hours after preparation, the result indicated that activation was significant(P<0.05).3.After water flush ,the bacteria detection rate of impression were decreased by 75.78%,still have remnant bacteria,main have staphylococci,streptococcus and Blastomyces albicans. 4. In hermetic condition,a 100% reduction of CFU was obtained with 30min wait after spraying of impression with 550mg/L chlorine dioxide,20min with 700mg/L chlorine dioxide,10min with 900mg/L chlorine dioxide.5. As to 550mg/L chlorine dioxide the reduction of 100% for 30min in the hermetic condition, and 99.75% in exposed to air, antibacterial effects in the hermetic condition were better than effects in exposed to air (P<0.05).6.The effects of different spraying disinfectant methods to alginate impressions. Study show that: 100% reduction of colony forming units was obtained with 30min wait after spraying of impression with 550mg/L chlorine dioxide, 20min with 20000mg/L glutaraldehyde and 0.1 % sodium hypochlorite.Conclution:l.Non-activited chlorine dioxide solution appeared to be more stable at low temperature than at room temperature. Activited chlorine dioxide solution for disinfection of mouth impression should be prepared at service time.2.Rinsing the impression could remove partial bacteria but still not enough.3.As chlorine dioxide concentration risen,the disinfecting time became shorten. 550mg/L chlorine dioxide for 30min and 900mg/L for 10 min could achieve an efficacious effect to alginate impression.4.As the fugitiveness of chlorine dioxide,disinfecting impressions could not exposed to air,put impressions in hermetic condition could avoid disinfectant content to loss.5. Compared with 20000mg/L glutaraldehyde and 0.1% sodium hypochlorite, 550mg/L chlorine dioxide have some advantages such as shortest action time, lowest working concentration, no stimulating smell and no adverse reaction to preferential use.