Abstract
The basic principles of infected root canal treatment in deciduous teeth are considered to be the same as those for permanent teeth removal of root canal contents and enlargement of the root canal for filling. However, it is true that the treatment of the deciduous root canal is more difficult than that of the permanent root canal because of various restrictions arising from the anatomical and physiological characteristics of deciduous teeth. Therefore, in this study, the propriety of the iontophoresis as a more successful method for root canal treatment was investigated. In particular, deciduous root resorption, harmfqlness to permanent successors, and effects on the eruption process were roentgenographically as well as microradiographically observed. Iontophoresis was performed in young dogs with deciduous molars using ammoniacal silver solution, iodine and zinc iodine solution. From the regular periodical investigations, the following conclusions were drawn.
The resorption of deciduous roots whose canals were filled after pulp extraction showed a tendency to retardation irrespective of whether iontophoreisi was performed or not. However, there were no significant findings which suggested the effects of iontophoresis on the resorption retardation. Concomitant with the retardation of root resorption, a tendency to retarded eruption of permanent successors was observed, while the uuantity of the formed dental germ remained unaffected. After natqral shedding of deciduous teeth, it was found that the permanent successors on the treated side showed a tendency to overtake those on the control side. Iontophoresis, which has, as mentioned above, no effect on formation and eruption of permanent successors when applied to the deciduous root canal treatment, is thought to be free from danger when applied to the cndodontic treatment of deciduous teeth.
