ABSTRACT
A method to sterilize the gypsum cast to prevent cross-contamination was investigated in the present study. Different dilution of cidex solution [2%, 1.5%, 1% and 0.5% glutaraldehyde] were mixed with stone powder instead of water. Microbiological study was done for the resultant stone casts after 1 hour and 2 hours from pouring contaminated impression. From the results obtained, it was concluded that, when cidex solution is mixed with stone powder instead of water it reduces or eliminates the microbial load of the resultant stone casts. Full strength cidex [2% glutaraldehyde] give the best results since it eliminates all the microbial load from the stone casts sterilize it, so, it is the recommended concentration of cidex to replace water in the stone mix. When cidex solution is diluted with water and mixed with stone powder, it reduces the microbial load but it fails to sterilize it completely. Stone casts which are produced by mixing cidex solution possess antimicrobial property. The highest level is achieved when cidex 2% is mixed with the stone powder