[Microbial contamination of water by pipe and hose material. 1. Detection of colony count changes].

Materials may produce a growth of microorganisms by contact with water. Pipes and hoses with a narrow diameter have not yet been tested on their influence on the microbial colonization of the water. A harmful change has been discussed especially in dental treatment units. Pipes and hoses were tested in their influence on the microbial growth for half a year. Glass, high grade steel, copper and PTFE showed no increase in microorganisms or only a little in the beginning. The other tested materials, PVC, PE, PA, silicon and rubber, produced an intensive microbial growth.