Comparison of the Efficacy of K-File, Canal Brush Technique, and Sonic Irrigation Technique in the Retrievability of Calcium Hydroxide and Metapex Intracanal Medicaments from Root Canals: An In vitro Cone-Beam Computed Tomography Analysis.

BACKGROUND AND OBJECTIVES: At present, none of the routinely used irrigating agents and activation techniques were able to completely remove the Ca(OH)2 intracanal medicament placed inside the root canal system during endodontic therapy. With this as the background, the aim of this study was to achieve complete removal of Ca(OH)2 when mixed with two different vehicles, using various irrigant activation techniques such as K-file, canal brush technique, and sonic irrigation technique, from the root canals of extracted human teeth. MATERIALS AND METHODS: Seventy-two mandibular premolar teeth with straight single root canal were selected and filled either with oil-based Metapex or calcium hydroxide powder mixed with distilled water and were activated using different activation techniques such as K-file, canal brush, and sonic MM1500 and NaOCl alone. Volumetric analysis was performed utilizing cone-beam computed tomography. RESULTS: None of the irrigants used were able to completely remove Ca(OH)2 from root canal. Sonic MM1500 showed significant removal efficacy than K-file, canal brush technique, and NaOCl for both aqueous-based and oil-based calcium hydroxide. CONCLUSION: Sonic MM1500 performed better than K-file, canal brush technique, and NaOCl in removing both Metapex and Ca(OH)2 powder. Regardless of the vehicles and agitation technique used, the remnants of Ca(OH)2 were present on all thirds of the canal walls.

The Evaluation of Dentin Microhardness After Use of 17% EDTA, 17% EGTA, 10% Citric Acid, MTAD Used as Chelating Agents Combined With 2.5% Sodium Hypochlorite After Rotary Instrumentation: An In Vitro SEM Study.

INTRODUCTION: The smear layer removed during root canal instrumentation enables penetration of irrigant solution and adhesion of root canal sealants providing a fluid tight seal of obturated root canals, necessitating its removal. The aim of the study was to compare the effect of smear layer removal by 17% Ethylene diamine tetraacetic acid (EDTA), 17% Ethylene glycol tetraacetic acid (EGTA),10% Citric acid and (MTAD solution) a Mixture of tetracycline isomer, an acid and a detergent applied as final rinse , when used along with 2.5% (NaOCl) Sodium hypochlorite and its effect on dentin microhardness. MATERIALS AND METHODS: Sixty single-rooted human mandibular premolars with minimum curvature (<5°) were instrumented using rotary instrumentation till apical enlargement size 35 RaCe file 0.04 taper. During instrumentation, the canals were irrigated with 2-mL 2.5% NaOCl. After instrumentation, teeth were rinsed with distilled water and were divided into 5 groups (n = 12) according to final rinse for 1 min with 5-mL 17% EDTA followed by 5-mL 2.5% NaOCl (group 1, control group), 17% EGTA (group 2), MTAD solution (group 3), 10% citric acid (group 4), and 17% EDTA (group 5). Teeth were split through the groove prepared, and one-half of specimen were evaluated for smear layer removal using scanning electron microscopy. A score system was followed to evaluate the images and comparisons among groups were performed using Kruskal-Wallis one-way analysis. Multiple comparisons were performed using Mann-Whitney U test. The other half was evaluated for dentin microhardness using Vickers microhardness testing machine. Microhardness values were statistically analyzed using parametric one-way analysis of variance test. CONCLUSION: Irrigation regimen following the use of 2.5% NaOCl during instrumentation followed by application of 5-mL 17% EDTA solution for 1 min resulted in efficient smear layer removal and less decrease in dentin microhardness compared with 17% EGTA, 10% citric acid, and MTAD solution.

Sealing ability of three root-end filling materials prepared using an erbium: Yttrium aluminium garnet laser and endosonic tip evaluated by confocal laser scanning microscopy.

AIMS: (1) To compare the sealing ability of mineral trioxide aggregate (MTA), Biodentine, and Chitra-calcium phosphate cement (CPC) when used as root-end filling, evaluated under confocal laser scanning microscope using Rhodamine B dye. (2) To evaluate effect of ultrasonic retroprep tip and an erbium:yttrium aluminium garnet (Er:YAG) laser on the integrity of three different root-end filling materials. MATERIALS AND METHODS: The root canals of 80 extracted teeth were instrumented and obturated with gutta-percha. The apical 3 mm of each tooth was resected and 3 mm root-end preparation was made using ultrasonic tip (n = 30) and Er:YAG laser (n = 30). MTA, Biodentine, and Chitra-CPC were used to restore 10 teeth each. The samples were coated with varnish and after drying, they were immersed in Rhodamine B dye for 24 h. The teeth were then rinsed, sectioned longitudinally, and observed under confocal laser scanning microscope. STATISTICAL ANALYSIS USED: Data were analyzed using one-way analysis of variance (ANOVA) and a post-hoc Tukey's test at P < 0.05 (R software version 3.1.0). RESULTS: Comparison of microleakage showed maximum peak value of 0.45 mm for Biodentine, 0.85 mm for MTA, and 1.05 mm for Chitra-CPC. The amount of dye penetration was found to be lesser in root ends prepared using Er:YAG laser when compared with ultrasonics, the difference was found to be statistically significant (P < 0.05). CONCLUSIONS: Root-end cavities prepared with Er:YAG laser and restored with Biodentine showed superior sealing ability compared to those prepared with ultrasonics.