The bacteria dentists use to determine Whether treatment of a root canal infection has been successful, namely the absence of discomfort and pain; x-ray evidence that abscessed areas, granulomas and cysts have completely filled in with new bone; and trust that the medicaments used in producing these results completely eradicated bacteria, all proved inadequate when such teeth were subjected to further testing by Dr. Price and his group.

Testing for the presence of bacteria in root canal, after the use of disinfectants which appeared to have controlled the infections, proved that the organisms had not been eradicated.

Dr. Price, in making cultures after the use of over 100 different medicaments, including different strengths of each, found only eight which had negative responses after 24 hours, and only two after 48 hours of incubation; longer periods were found to be ineffective as medicaments lost their disinfecting power.

The two most efficient medicaments proved to be objectionable - silver nitrate because it turned teeth black and formalin because it was very irritating and painful to patients and destructive to surrounding tissues.

Though culturing to determine whether bacteria had been killed was formerly taught and practiced, I know of no dentists using such a testing procedure today.

Dr. Price in another series of tests took extracted infected teeth and treated them (much easier to do aseptically outside of the mouth) and found when these teeth were sectioned their dentin and cementum were still infected.

In still another investigation, Dr. Price made biopsy sections at and below the gum line and found bacteria present not only in the root of the teeth and their protective cementum but also in the first millimeter or two of adjacent bone. The importance of this factor in causing cavitations in bone after extractions will be discussed in a later chapter.

Dr. Price noted future developments might bring forth medicaments which are more successful. You will all be thinking that antibiotics are certainly the answer. However, antibiotics have not proven able to effectively penetrate the dentin tubules, cementum and adjacent bone sufficiently to eradicate these bacteria.

Testing of new medicaments, and current efforts such as new laser treatment methods, are of course necessary and were anticipated by Dr. Price.

All of these root canal side-effect problems should not deter the profession from continuing to explore new methods of how to save teeth. While we cannot learn how to save teeth by extracting them, Dr. Price fortunately has shown us ways to test procedures to prove whether infection has been eradicated in teeth we think we have saved.