Introduction: The purpose of this in vitro study was to compare and evaluate the formation of dentinal microcracks after root canal preparation while using four single reciprocating file systems [WaveOne (WO), Reciproc (RC), WaveOne Gold (WOG), Reciproc Blue (RCB)]. Materials and methods: Seventy-five extracted mandibular premolars were randomly selected. A total of 15 teeth were left unprepared and served as control, and the remaining 60 teeth were divided into four groups. WaveOne files, Reciproc files, WaveOne Gold files, and Reciproc Blue files were used to prepare the canals. Roots were then sectioned at 3, 6, and 9 mm from the apex and the cut surface was observed under the scanning electron microscope (SEM) for the presence of dentinal microcracks. Results: The control group were not associated with microcracks, while all the single file systems tested resulted in dentinal microcrack formation. Among the groups, tooth prepared with WaveOne Gold and Reciproc Blue files showed fewer cracks than other experimental groups; however, no significant difference was found between them (p > 0.05). Conclusion: Root canal preparation with reciprocating files resulted in dentinal microcracks. WaveOne Gold and Reciproc Blue files caused less microcracks than WaveOne and Reciproc files. Heat-treated instrument produced less microcracks than M-wire instruments.

Aim: To compare and evaluate the antibacterial efficacy of calcium hydroxide (CH) paste, triple antibiotic paste (TAP), and double antibiotic paste (DAP). Materials and methods: Ninety patients with ninety single-rooted teeth were selected. After complete disinfection, access opening was made and sample S1 was collected with paper point after injecting 5 mL of normal saline. After working length determination and biomechanical preparation till #40 K-file, sample S2 was collected in the same manner as S1. The canals were dried and the three intracanal medicaments were mixed with propylene glycol. The patients were randomly divided into three groups (n = 30) and the medicaments (group I—CH, group II—TAP, and group III—DAP) were placed. After 7 days, following medicament removal, sample S3 was collected. Microbiological samples (S1, S2, and S3) were preincubated for 30 minutes and then plated on brain heart infusion agar and colonies were counted after 24 hours using the classic bacterial counting method. Results: There was significant reduction of bacterial count from stages S1 to S2 and S2 to S3 in all the three experimental groups. The maximum reduction of bacterial count (CFU/mL × 10⁵) at S1, S2, and S3 stages and reduction in mean was seen in group III. However, there were no statistically significant difference between group II (TAP) and group III (DAP). Conclusion: The TAP and DAP have similar antimicrobial efficacy though better than CH.

Aim: To compare and evaluate the effect of two different sealer placement techniques on the apical sealing ability of MTA Fillapex and AH Plus root canal sealers. Materials and methods: Study was performed on 40 extracted human single-rooted permanent teeth, which were decoronated and the root canals were instrumented. The specimens were randomly divided into four groups and obturated using single-cone technique. Group IA: Using AH Plus sealer; placed using master gutta percha (GP) cone, group IB: Using AH Plus sealer; placed using size 30 lentulospiral, group IIA: Using MTA Fillapex; placed using master GP cone, and group IIB: Using MTA Fillapex; placed using size 30 lentulospiral. Microleakage was evaluated using dye penetration method. Teeth were split longitudinally and then horizontal markings were made at 1.5, 4, and 6 mm from the apex. Dye penetration evaluation was performed under stereomicroscope (4× magnification) and statistically evaluated. Results: The lowest microleakage values were obtained with group IIB (MTA Fillapex placed using lentulospiral) and the highest with group IA (AH Plus placed using mastercone). Conclusion: Within the limitations of the study, MTA Fillapex sealer placed using lentulospiral achieved highest apical seal among the experimental groups. Though leakage cannot be totally eliminated from the fate of a root canal treated teeth, the type of root canal sealer and its placement plays a major role in the success of an endodontic treatment.

Background: The success of endodontic treatment depends on the exploration, proper cleaning, disinfection, and obturation of the entire root canal system. Maxillary first molar is a tooth with wide-ranging root canal configurations. A dental operating microscope provides better visualization of the pulp chamber floor. Cone-beam computed tomography (CBCT) can be used as a good tool for understanding root canal morphology and very few cases were reported using CBCT scanning. Case description: This case repot discusses about a maxillary first molar with three roots and six root canals. Root canal configuration was diagnosed with the aid of a dental operating microscope and confirmed with CBCT. The CBCT axial images showed the Vertucci type II canal pattern in all the three roots. The pulp chamber was modified from conventional triangular access to rhomboidal shape to explore additional canals and root canal preparation was done. Conclusion: The maxillary first molar is a tooth with wide variations in root canal morphology. Use of a dental operating microscope is of great help in such cases and use of CBCT images helps to understand the rare root canal configuration. Clinical significance: A wide range of root canal variations are reported with the first maxillary molar. The use of a dental operating microscope and CBCT helps in better understanding of such variations in root canal configuration. Root canal treatment done with these tools can provide better treatment outcome.

Background: Irrigation is an integral part of successful root canal treatment. Syringe and needle irrigation is an effective method to control microbial flora of the root canal. Needle with multiple vents efficiently delivers irrigating solutions. Geometric configuration of the irrigating needle may predispose it to fracture during irrigation. A fractured needle causes procedural difficulties during treatment. Careful removal of the fragment with minimal tissue loss improves the prognosis of the treatment. Case description: This case report describes the management of a fractured double-side-vented irrigating needle within the mesiobuccal canal orifice of maxillary first molar. The separated fragment was successfully retrieved with the help of indirect ultrasonics under magnification with a dental operating microscope. Conclusion: Development in techniques and armamentarium has led to successful retrieval of separated fragment from the root canal. The selection of a suitable method according to the position of the fractured instrument facilitates retrieval with minimal tissue removal.