Quantitative bacteriology of endodontic infections.

A technique is described for obtaining quantitative cultures of endodontic specimens. Paper point samplings were placed in a diluted salt solution, vortexed, and then cultured quantitatively using serial dilutions plated onto multiple media. Specimen weight was determined by weighing the point before and after specimen collection. This method was used in 10 nonvital teeth and showed a mean concentration of 10(7.7) bacteria per gram of sample. Nine specimens yielded a mixed aerobic-anaerobic flora, and there was an average of five different bacterial species per specimen in concentrations exceeding 10(5)/gm.