USE OF THE GERMFREE ANIMAL TECHNIC IN THE STUDY OF EXPERIMENTAL DENTAL CARIES

I. BASIC OBSERVATIONS ON RATS REARED FREE OF ALL MICROORGANISMS

¹ Walter G. Zoller Memorial Dental Clinic and the Department of Bacteriology and Parasitology, University of Chicago, Chicago, Ill.
² Lobund Institute for Research in the Life Sciences, University of Notre Dame, Notre Dame, Ind.

Methods and technics for adopting the procedures of germfree rearing of animals to the study of experimental dental caries have been described in this first and complete report on the initial phase of the study.

Findings indicated that twenty-two rats (Rattus norvegicus albinus) reared under germfree conditions remained entirely free of even microscopically demonstrable dental caries. Of thirty-nine conventional control rats, possessing the usual mixed microbial populations, thirty-eight developed carious lesions when maintained on the same kind of dietary regime as the germfree animals.

It is deduced from this evidence that dental caries in the rat is not possible in the absence of microorganisms.