Abstract : The purpose of this study was to investigate whether two types of root canal sealer affect the onset of postoperative pain after root canal filling.

 At Kyushu Dental University Hospital, seven dentists performed infected root canal treatments for 60 patients with periapical lesion. In the root canal filling, non-eugenol root canal sealer was used for 30 patients (non-eugenol group), and 4-META-containing resin-based root canal sealer for the other 30 (resin group). The choice of sealer was randomized. After the root canal filling, the rate and factors of postoperative pain were analyzed.

 As a result, postoperative pain was observed in a few cases in both groups, and no significant difference in the rate of postoperative pain was found between the two groups. Two weeks after the root canal filling, postoperative pain had disappeared in almost all cases, except one case of the non-eugenol group. Gender, age and type of tooth seemed to affect the frequency of postoperative pain, although there was no significant difference between the groups.

 These results suggest that the two root canal sealers examined in the present study may not affect the onset of postoperative pain.

Abstract : Purpose : The purpose of this study was to evaluate the apical sealing of MTA-based root canal sealer (MTA-Fillapex, Endoseal) and resin-based root canal sealer (AH plus jet) as a control.

 Materials and Method : A total of 72 plastic teeth (Thermafil training block) were prepared for the experiment. The remainder teeth prepared 7% tapered #25 canal. The six groups were separated and obturation by single cone technique and THERMA-PREP 2 with Guttacore. The sealing ability of MTA-based root canal sealers was evaluated by dye leakage test. A one-way analysis of variance (ANOVA) and Scheffe’s test were used to compare and identify any statistically significant differences at p<0.05.

 Results : The sealing ability of MTA-based root canal sealers was significantly lower than that of AH plus jet. The sealing ability of MTA-Fillapex was better than that of Endoseal, although not significantly different from those of single GPP and/or THERMA-PREP 2 with Guttacore for each root canal sealer.

 Conclusions : This study confirmed that the sealing ability of MTA-based root canal sealers was significantly lower than that of resin-based root canal sealer.

Abstract : Purpose : The aim of this study was to assess the root and root canal morphology of mandibular premolars in a Japanese population using dental cone-beam computed tomography (CBCT).

 Materials and methods : We analyzed the CBCT images of 286 first premolars and 280 second premolars from 145 patients. The following parameters were evaluated on CBCT : (1) number of roots and root canals ; (2) the classification of root canal configuration according to Vertucci’s criteria.

 Results : The majority of the first and second mandibular premolars had one root (98.3% of the first premolars and 100.0% of the second premolars) ; in addition, two roots were identified in 1.7% of the first premolars. The most prevalent root canal frequency was as follows : one canal (77.0%), two canals (19.2%), and three canals (1.8%) for single-rooted first mandibular premolars ; one canal (98.2%) and two canals (1.4%) for second premolars. The most predominant root canal morphologies for single-rooted first mandibular premolars were Vertucci’s type I (78.6%), followed by type V (14.6%), type III (5.0%), and type VIII (1.8%) configurations ; the most predominant root canal morphologies for second mandibular premolars were type I (98.6%) and type V (1.4%) configurations.

 Conclusion : First mandibular premolars exhibited high variability and complexity in their canal system. On the contrary, the root and root canal configurations of second mandibular premolars showed a lower degree of variability compared with first mandibular premolars.

Abstract : Apicoectomy and other endodontic surgery may be used as adjuvant treatment for cases where conventional root canal treatment has not been successful or for cases where treatment with fixed prostheses is not possible. In some cases, however, apicoectomy may be extremely difficult or even impossible due to anatomical conditions or other considerations. Apicoectomy can normally be performed up to the mesial root of the first molars, but this treatment cannot reliably be performed on the palatal or distal roots of those teeth and the second molars. Because the anatomical position makes it difficult to insert the instruments and operate, intentional replantation is effective in such cases.

 We report two cases in which intentional replantation was used to treat teeth that would be exposed to the risk of root fracture by removing abutments. Root end resection and retrograde root canal filling were also performed in both of these cases. Intentional replantation is a highly successful surgical endodontic technique that can be carried out rapidly during the operating procedure. In the first case, however, a shadow suggestive of external root resorption became apparent 5.5 years postoperatively. Bone ankylosis to the root and external resorption may occur in intentional replantation. The widespread adoption of cone-beam computed tomography and dental microscopy have dramatically improved the success rate of endodontic surgery, and these devices should also be used proactively for intentional replantation.