Abstract : Purpose : The aim of this study was to compare the glide path preparation times of three different techniques in constricted canals. Optimum Glide Path 2 (OGP2) is a new reciprocating motion designed to prepare glide paths efficiently.

 Methods : Thirty-three human constricted single root canals, with initial apical size no longer than ISO#8, were selected and negotiated with #6−#8 C⁺ files under the microscope. Canals were randomly divided into three groups : Group 1 (CR, n=11) : ProGlider was used with continuous rotation motion (300 rpm/2 N), Group 2 (OGP2, n=11) : ProGlider was used with OGP2 motion, and Group 3 (MAN, n=11) : glide path was established by using #10−#15 stainless steel K-files manually. Glide path preparation times were recorded with an electronic stopwatch. The data was analyzed using one-way analysis of variance followed by Tukey-Kramer’s multiple test.

 Results : Mechanical glide path preparation was significantly faster than manual glide path preparation (p<0.01). There was no statistically significant difference in the mean glide path preparation times between Group 1 (CR, n=11) and Group 2 (OGP2, n=11).

 Conclusion : The mechanical glide path technique resulted in a statistically significantly faster glide path preparation time than the manual glide path technique.

Abstract : Purpose : The purpose of this study was to investigate the effect of various root canal sealers on the sealability and removability of root canals.

 Materials and Methods : The root canal was cut so that the root length was 10 mm, and the upper part of the root canal was enlarged with a Gates Glidden drill to #70. After cleaning the root canal, three filling methods were used : lateral pressure filling, single-point filling, and filling with sealer only, using MetaSEAL Soft paste (Sun Medical), MetaSEAL Soft (Sun Medical), Canals N (GC SHOWAYAKUHIN), AH Plus Jet (Dentsply Sirona), and Nishika Canal Sealer BG multi (Nippon Shika Yakuhin). Dye infiltration tests were then performed. The same sealer was also used to perform root canal filling using a transparent root canal model, followed by evaluation of removability.

 Results and Discussion : For sealer-only filling, Canals N showed significantly higher leakage than the other four sealers as well as the single-point method (p<0.05). MetaSEAL Soft paste and MetaSEAL Soft showed almost no leakage. In addition, in the evaluation of removability, MetaSEAL Soft was able to be removed in the shortest time.

 Conclusion : MetaSEAL Soft paste and MetaSEAL Soft were shown to have the best sealing properties. In addition, in terms of filling method, filling with sealer only was shown to be the most superior. In the evaluation of removability, the sealer-only method showed that it could be removed in a shorter time, suggesting that the root canal filling method needs to be improved.

Abstract : Mandibular premolars with C-shaped root canal are not common, yet are one of the most challenging tooth morphologies encountered by endodontists. Here, we report the case of a 70-year-old female patient whose mandibular left first premolar was diagnosed as symptomatic apical periodontitis and was subsequently treated endodontically. The patient presented 1 month later with a reflected sinus tract in the gingiva of the mandibular left first premolar. After successful treatment with endodontic microsurgery, periapical radiolucency around the root of the tooth was improved at the 14-month postoperative recall. This case suggests that preserving a complicated tooth in which even instrumentation is difficult can be achieved with precise root-end resection under a microscope at high magnification.