Abstract : A periapical lesion that does not resolve following conventional endodontic therapy should be surgically treated. These surgical aids to endodontics are called surgical endodontics. Apicoectomy is one of them, and is the commonest.

 In this paper, some clinical issues of apicoectomy are discussed.

Abstract : In the previous study, we have reported that generated hydroxyl radical (•OH) from Cu²⁺ and H₂O₂ mixed solution had bactericidal effect and also changed shape of the smear layer of root canal wall into hyaloid structure. This hyaloid structure was removed with EDTA. In this study, we examined changing form of hyaloid structure on treatmen time of Cu²⁺ and H₂O₂ mixed solution, and also examined changing form of hyaloid structure after using EDTA, by SEM observation. In the results, the hyaloid structure was formed after 1 min irrigated by Cu²⁺ and H₂O₂ mixed solution, and growing by irrigation time. When irrigate root canal wall with Cu²⁺ and H₂O₂ mixed solution over 2 min and then using EDTA, collagen fiber and layer were observed clearly without destroy of orifices of dentinal tubules.

Abstract : After removal of pulp, root canal wall was irrigated by EDTA, NaClO, and H₂O₂. The clear dentinal tubules and calcospherites were observed by scanning electron microscope (SEM). Fluorides (SnF₂ and NaF) were applied the root canal walls after removal of pulp. By the fluoride application, some types of particle were observed, and those were becoming bigger according the extention of application time.

 The almost root canal surfaces were covered with particles and dentinal tubeles were not observed in the case of 10 min application. Therfore, it is supposed that the fluoride application to root canal dentin without pulp and smear layer, is an effective method of making barrier for protection of irritants leakege.

Abstract : The mandibular first premolar usually has one canal one foramen. However, sometimes we meet with complicated canal and foramen. In this case report, the patient has the mandibular first premolar with two canals and two foramens. The patient had discomfort and pain sometimes on the mandibular first premolar for 10 years. In addition, the tooth has deep pocket with severe mobility. During past 10 years, several dentists tried to treat this tooth, but the results were not satisfactory. When the patient was sent to us, the tooth was found to have two canals. After the root canals were treated and filled, satisfactorily prognosis was obtained.

 Clinical symptoms e. g. mobility, deep pocket and discomfort were improved greatly. In the endodontic therapy, we must pay attention to tooth anatomy for obtaining success of root canal treatment.

Abstract : In the endodontic therapy, when perforation occur at the furcated area of multirooted tooth, the first choice is to close down from the side of the pulp floor. However, in the case of prognosis to be bad, the close down procedure from outer surface root of the tooth, separation, hemisection, and replantation will be selected.

 In this case report, the patient has the big perforation of about 3-4 mm at the furcation area of the upper first molar. The perforation part was closed down from the side of the pulp floor with the apatite cement.

 After 1 year, prognosis was bad. So we decided to try intentional replantation. After extraction, the perforation part was closed by apatite cement and the root apex was retrofilled by glass ionomer cement. At this time, the perforation between the mediobuccal root and the palatal root, and also communication of the maxillary sinus were confirmed. After irigation, curetting of this part, the tooth was replanted.

 After 1 year, the patient had no clinical symptoms.

 The treatment of the odontogenic maxillary sinusitis is extraction of the cause tooth or the sinusectomy. However, the method for this case did not spend long time for the treatment and could remove infected part easily. In addition, it was possible to preserve the tooth with intentional replantation.

 It is considered that this method is effective for odontogenic maxillary sinusitis due to perforation of the furcation area.