Periodontal Disease in the 18-Month-Old Germfree Rat

We havc previously shown that periodontal disease occurs in germifree mice (P. N. BAER and W. L. NEWTON, Oral Surg., Or;al iMed., & Or;al Path., 13:1134-44, 1960; J. 1'eriodont., 35:388-96, 1964). It was the purpose of this investigation to determine whether iseriodontal disease also occurred in germfree rats. The jaxvs and teeth of 5 female and 3 male, 18-month-old Sprague Dawley germfree rats, xw hich present. (2) There were periodontal lesions in which the primary etiologic factor probably was the traumatic imlpaction of hair or food or 1oth (Fig. 2). The gross defleshed specimens (Fig. 3) showed extensive occlusal xwear and severe alveolar bone loss about the molar teeth. Periodontal disease occurred in all the 18-monthold germfree rats studied.