An analysis of the sensitivity of non-rereduced PRS medium in endodontic therapy.

A total of 244 paired samples were obtained from sixty-one root canal systems at four specific stages of endodontic treatment. Half the samples were placed in a commonly used endodontic medium and incubated aerobically. The remaining samples were placed in PRS medium and incubated in an anaerobic environment. The rereduction procedure, used to remove oxygen entering the PRS medium at the time of insertion of the sample, was not employed. A statistical analysis of the results indicates that the non-rereduced PRS medium is not as sensitive as rereduced PRS and offers no significant advantages over trypticase soy broth with 0.1 percent agar.