Abstract
here are various restrictions on the root canal filling of deciduous roots after root canal treatment unlike in the case of permanent teeth, because deciduous molars undergo physiological root resorption with aging. Among the restrictions, it is most important that the root canal filling material be similarly absorbed and disappear along with the deciduous root so that it does not prevent the eruption of the permanent successors. Hardly any of the root canal filling materials currently on the market, however, are suitable for deciduous molars because some of them disappear earlier than the deciduous root without becoming indurated in the root canal, while some delay tooth replacement because they are resorbed with great difficulty, and continue strongly to stimulate the surrounding tissue of the root apex. Root canal filling materials utilizing α-TCP and hydroxyapatite with excellent biocompatibility have recently been put on the market by Sankin Kygyo Co. Type-III, in particular, contains only 5% iodoform, causing only very slight stimulation, and is a relatively good product from a practical standpoint, i. e., filling the root canal using a lentulo.