Introduction:The main aim of root canal treatment is cleaning, shaping and then obturating three dimensionally to prevent reinfection. This includes chemicomechanical cleansing by instrumentation and the use of irrigating solutions. Therefore, the purpose of this study was to compare the smear layer removal from root canal dentine subjected to two root canal irrigants, 17% EDTA and 0.2% Chitosan, a new irrigant using Scanning Electron Microscope.Methodology:40 single rooted premolars were decoronated followed by instrumentation with I Race files and intermediate irrigation with 3% sodium hypochlorite and activation with ultrasonics. Then the samples were longitudinally sectioned and place in the respective test solutions and their controls for 5 minutes. Scanning Electron Microscopic evaluation was further carried out.Results:The results of the present study indicates that the Chitosan which was proved effective in removing smear layer.Conclusion:A moderate concentration of 0.2% chitosan removes the smear layer with greater efficiency.

Aim: The aim of this study was to compare the effect of diode laser, endoActivator, and passive ultrasonics for smear layer removal at the apical third from root canals with 0.2% chitosan. Materials and Methods: A total of 40 mandibular premolars were decoronated to establish a working length of 12 mm and shaped with ProTaper rotary files up to size F3. In Group A, canals were irrigated with 1 ml of 0.2% chitosan. In Group B, canals were initially irrigated with 0.8 ml of 0.2% chitosan and the remaining 0.2 ml was activated with diode laser. In Group C, canals were irrigated with 1 ml of 0.2% chitosan which was activated with endoActivator. In Group D, canals were irrigated with 0.2% chitosan and activated with passive ultrasonics. All samples were finally flushed with 3 ml of distilled water. The percentage of smear layer removal was analyzed with a scanning electron microscope examination at ×1000 and ×3000. Data were analyzed using Statistical Package for the Social Sciences version 16.0 (SPSS Inc., Chicago, IL, USA) at a significance level of P < 0.05. Results: The mean value for Group B when compared to Group C for the removal of smear layer was higher, but there was no statistically significant difference between the two groups ( P < 0.068 and P < 0.295). Both Group B and Group C showed a statistically significant difference ( P < 0.001) when compared to Group A and Group D for the removal of smear layer. Conclusion: Diode laser and endoActivator with 0.2% chitosan proved better in the removal of the smear layer when compared to passive ultrasonic irrigation.

AIM: The study aimed to investigate the penetration depth of calcium hydroxide-based root canal sealer into buccolingual and mesiodistal aspects of roots with and without the butterfly effect at coronal and middle root sections. METHODS AND MATERIALS: Twenty single-rooted maxillary premolars were decoronated at the cementoenamel junction and viewed under a light microscope and grouped as Group 1 – butterfly (B) and Group 2 – non-butterfly according to the presence or absence of the effect. Canals were prepared till working length followed with copious irrigation. Canals were finally rinsed with 5 ml of 17% ethylenediaminetetraacetic acid solution and activated using EndoActivator followed by obturation using gutta-percha (warm vertical compaction technique) with Sealapex sealer. To provide fluorescence for confocal laser scanning microscopy (CLSM), the Sealapex was mixed with rhodamine B dye. Root sectioning yielded coronal and middle sections. CLSM was used to assess the penetration of the sealer. STATISTICAL ANALYSIS: Shapiro–Wilk test, unpaired “t-test.” RESULTS: Teeth with the butterfly effect had greater mean penetration buccolingually (905.2 μm) than mesiodistally (182.1 μm; p < 0.001). Coronal sections had greater penetration (517.4 μm) compared with the middle (354.6 μm). CONCLUSION: Sealapex sealer exhibited maximum tubular penetration in teeth with butterfly effect in buccolingual direction at the coronal third level.