Aim:The aim of the present study was to compare the canal transportation and centering ability of three rotary nickel-titanium (NiTi) systems (Twisted Files [TF], HyFlex controlled memory [CM], and Wave One [WO]) in curved root canals using computed tomography (CT).Materials and Methods:Sixty freshly extracted single-rooted teeth having curved root canals with at least 25–35 degrees of curvature were selected. The teeth were randomly divided into three experimental groups of twenty each. After preparation with TF, HyFlex CM, and WO, all teeth were scanned using CT to determine the root canal shape. Pre- and post-instrumentation images were obtained at three levels, 3 mm apical, 9 mm middle, and 15 mm coronal above the apical foramen were compared using CT software. Amount of transportation and centering ability were assessed. The three groups were statistically compared with analysis of variance and post hoc Tukey's honestly significant difference test.Results:Least apical transportation and higher centering ability were seen in HyFlex CM file system in all the three sections followed by TF. WO file system showed maximum transportation.Conclusions:The canal preparation with HyFlex CM file system showed lesser transportation and better centering ability than TF, WO file system.

Trauma may result in craze lines on the enamel surface, one or more fractured cusps of posterior teeth, cracked tooth syndrome, splitting of posterior teeth, and vertical fracture of root. Out of these, management of some fractures is of great challenge and such teeth are generally recommended for extraction. Literature search reveals attempts to manage such fractures by full cast crown, orthodontic wires, and so forth, in which consideration was given to extracoronal splinting only. However, due to advancement in materials and technologies, intracoronal splinting can be achieved as well. In this case report, longitudinal fractures in tooth #27, tooth #37, and tooth #46 had occurred. In #27, fracture line was running mesiodistally involving the pulpal floor resulting in a split tooth. In teeth 37 and 46, fractures of the mesiobuccal cusp and mesiolingual cusp were observed, respectively. They were restored with cast gold inlay and full cast crown, respectively. Longitudinal fracture of 27 was treated with an innovative approach using intracanal reinforced composite with Ribbond, external reinforcement with an orthodontic band, and full cast metal crown to splint the split tooth.

Aim: The purpose of this article is to determine the racial predilection of C-shaped canal configuration in a mandibular second molar. Background: Unusual root canal anatomy always poses a diagnostic and treatment challenge. Identification of such variation is important for the success of root canal treatment outcome. C-shaped canal configuration is such an aberrant morphology of molar teeth that vary in different population and is commonly seen in a mandibular second molar. Thus, knowledge of racial predilection of C-shaped canal configuration in different population for early diagnosis is obligatory. Materials and Methods: An exhaustive search was undertaken to identify published research articles related to C-shaped canal configuration in mandibular second molars. Forty-three research articles were analyzed which included 12,481 mandibular second molars. Chi-square test using value of P < 0.05 was performed to assess the statistical significance of this anomalous anatomic variation among the different population. Results: Statistical test revealed a significant variation between the Asian and nonAsian population. The highest incidence of racial predilection was observed in China (Asia) with 93.1%, and the minimum was observed in America with 2.7%. Conclusion: This research reported that racial predilection of C-shaped canal configuration in mandibular second molar varies significantly.

Mandibular molar with extensive loss of tooth structure, especially where no cavity wall is remaining, and insertion of posts in both the roots appear necessary so as to achieve proper retention for the core material. A single unit metal casting with two posts, one in the mesial root and the other in the distal divergent root, is difficult to fabricate due to difference in the path of insertion of the two posts. Multisection post and core or single cast post and core with auxiliary post can be an effective design to manage grossly decayed mandibular molars.

Aim: To compare the effect of smear layer removal with 17% EDTA and Nd:YAG laser on the apical microleakage of two resin based sealers. Materials and Methods: Sixty freshly extracted maxillary central incisor teeth with patent canals were selected. The teeth were debrided and stored in saline for 24 hours before use. The teeth were sectioned at CEJ & cleaning and shaping were done upto 50 size by step back technique. The following groups were analyzed. GROUP 1:  Gutta percha (GP) + AH plus sealer without smear layer removal. GROUP 2:  GP + RC seal sealer without smear layer removal. GROUP 3:  GP + AH plus treated with 17% EDTA. GROUP 4:  GP + RC seal treated with 17% EDTA. GROUP 5:  GP + AH plus treated with Nd:YAG laser. GROUP 6:  GP + RC seal treated with Nd:YAG laser. 8 samples were subjected to dye penetration study for apical microleakage & 2 samples were subjected to SEM in each group to show the effect of smear layer removal by EDTA and laser. The data were analyzed by using ANOVA and TUKEY-HSD test. Results: Groups 1 and 2 showed maximum microleakage , other groups showed lesser microleakage but there was no statistically significant difference between laser and EDTA treated Groups.  Conclusion: EDTA and Nd:YAG laser can be effectively used to  remove smear layer and showed less apical microleakage compared to non-treated groups. Keywords: 17% EDTA, Nd:YAG LASER , AH plus , RC sealer ,  Smear layer.