In Japan, for over 1,000 years in the past, the people had a popular habit of the Tooth-Black, dyeing their teeth in black, which at the same time served to prevent the dental caries. The ingredients of the Tooth-Black act on the organic and inorganic structures of the teeth, and prevent the teeth from dissolution.

  In application of the mechanism of this Tooth-Black, Tannin-Fluoride Preparation (HY agent) was originated for the dental application, which causes no discoloration of the teeth applied. The HY agent possesses remarkable characteristics, both basically and clinically, as shown in the following table (Tab. 2). Moreover, the temporary and permanent cements (HY cements as preventive dental materials) added with the HY agent were developed, both of which have shown the same clinical merits.

  In spite of our heavily packed everyday schedule, it is utmost important for us, the general practioners, to review from one case to another its physiological and pathological manifestations of dental pulp and its morphology of root canals.

  Personally I think nine of ten dentists in Japan do not prefer to Endodontic-treatment under the National Health Insurance programs.

  Because it depend on the technical problem for root canal formation or preparation on time to general dentistry.

  Them, how to do our practice it Endodontics at diaIy?

  As followings are my basic concepts on my Endo-practice :

  (1) Removed of necrotic dentin completely at first.

  (2) Restoration should be due to composite resin.

  (3) Always need to water calant system due to cavity preparation.

  (4) Always need to chech up for restoration's margin.