Bacteria were also recovered from the periapical soft tissue lesion surrounding the cementum, but not from dentin adjacent to the cementum, suggesting that the organisms may have entered the lesion directly from the root canal space. Also in such a situation antimicrobials with an ability to penetrate the soft tissue lesion outside the apical foramina seem warranted. Small cavities, serving as wells for the placement of a bacterial cell suspension of E. coli , were then prepared parallel to the root canal space in intact root dentin of single-rooted teeth. Clear zones of growth inhibition were observed around all test teeth, but were never seen with the controls. Except for one specimen, in which a few bacteria were isolated, no bacteria were recovered after 24 hours of inoculation.
Findings also show that they are able to penetrate deep into dentin.
The antimicrobials tested also seem to provide a distant antimicrobial effect along apical foramina. On the basis of these observations we conclude that an intracanal dressing of MN, ciprofloxacin and minocycline should be a valuable adjunct to the treatment of infected root canals. Acknowledgment The author is grateful to Professor Hoshino, Professor Ozawa, Professor Noda and many other co-investigators of the Cariology Group, at the Niigata University School of Dentistry for their scientific contributions to this review paper. Hoshino E, Ando N, Kota K. Bacterial invasion of non-exposed dental pulp. Hoshino E. Predominant obligate anaerobes in human carious dentin.