The Effect Of Disinfectants On Dimensional Stability Of Agar Alginate Combined Impressions

Objective: To evaluate the effect of disinfection on three-dimensional accuracy of alginate agar combined impression material after different treatment with three disinfectant solutions : 2% alkaline glutaraldehyde, 1%84 disinfector, 0.5% iodophor. The results may give some instructions for the clinical application.Materials and methods: One hundred and thirty alginate agar combined impressions were made with the same mould and individual trays. They were divided into thirteen groups and ten samples in every group.Among them,one group was rinse with distilled water as control ,the others were treated with 2% alkaline glutaraldehyde , 1%84 disinfector , 0.5% iodophor respectively by spray or immersion of 10min,20 min and 30 min .Then the impressions were poured in dental stone and taken off 40 minutes later. After 24 hours the samples were measured with a microscope. The experiment data were analyzed with the SPSS 11.0 software.Results: There was no significant difference between the control and every spraying group (P>0.05) .Significant difference was found between all immersion groups and control (P<0.05) and the difference increased along with the prolonging of time. There was no significant difference between every same group of 2% alkaline glutaraldehyde and 1%84 disinfector (P>0.05) .Samples treated with 0.5% iodophor had significant difference in 30 min immersion group (P>0.05) and no significant difference in other group when compared with 2% alkaline glutaraldehyde and 1%84 disinfector.Conclusion: Spray treatment with 2% alkaline glutaraldehyde, 1%84 disinfector ,0.5% iodophor has no significant effect on dimension changes of agar alginate combined impressions . Dimension change of impressions being immersed in disinfectants within 20 min is acceptable on clinical use and it will not affect the accuracy of fixed prosthesises .