Bacterial contamination of dental radiographic film.

Three types of paper-covered and one type of plastic-covered Kodak dental film were used to determine if bacteria could penetrate the coverings and contaminate the inner film. Films from each group were immersed for 30 or 120 seconds in high concentrations of known bacterial suspensions with or without 10% sterilized calf serum added to the incubation media. The plastic-covered film effectively excluded all bacteria, whereas the paper-covered film showed contamination with all organisms even at 30 seconds. Increasing the viscosity of the incubation medium with calf serum decreased the level of contamination.