Comparative Analysis of Three Nickel-Titanium Rotary Files in Severely Curved L-Shaped Root Canals: Preparation Time, Aberrations, and Fracture Rates.

Background: This simulated study of 30 severely curved L-shaped root canals aimed to compare preparation time, aberrations, width measurements, and fractured files of three nickel-titanium (Ni-Ti) files, namely, ProTaper, ProTaper Next (PTN), and WaveOne (WO). Methods: Thirty simulated L-curved root canals of resin blocks were randomly divided into three groups. The canals were prepared to a tip size of 25 using ProTaper, PTN, and WO rotary file systems. Pre- and post-operative views for each sample were captured by a professional camera at a standardized distance and position. Blue India ink was injected into the pre-operative canals, and red India ink was injected into the post-operative canals to give a clear superimposition image. Five points were assessed through the halfway of the canal to the orifice (area between the beginning of curvature and apical end point). Preparation time, aberrations, width measurements, and fractured files were recorded and analyzed. Results: Mean preparation time was longest in ProTaper (4.89±0.68 minutes). PTN and WO were the fastest in preparing the canals (about 3 minutes). A statistically significant difference was found between WO and ProTaper & PTN and ProTaper (p=0.000), while the difference was non-significant (p > 0.05) between WO and PTN. Nine aberrations consisting of three zips, one ledge and one outer widening were related to ProTaper, while WO recorded a ledge and fractured file, but for PTN system, it verified an outer widening and ledge. Only one WO file fractured, with no deformation observed in the other instruments. No significance was recorded among the width measurements in the different levels. Conclusion: ProTaper next achieved faster cutting than the ProTaper and WO file systems. PTN maintained the best apical termination position and produced the least canal aberration, followed by WO and ProTaper.

Analysis of Root Canal Characteristics in Permanent Canine Teeth Among 270 Saudi Subjects: A Cone-Beam Computed Tomography Study.

BACKGROUND An understanding of root canal morphology is vital for successful endodontic treatment. However, variations in the root canal system of permanent canines, especially in relation to population-based diversity, are not well-documented. This study thus aimed to analyze the root canal numbers, configurations, and bilateral symmetry in 1080 permanent canine teeth among 270 Saudi individuals using cone-beam computed tomography (CBCT), contributing to the existing body of knowledge and aiding clinicians in devising effective treatment strategies. MATERIAL AND METHODS The CBCT images of 270 participants, encompassing 1080 canines (540 pairs of upper and lower canines), were scrutinized for root and canal counts. Canal configurations were assessed based on Ahmed's and Vertucci's classifications. Bilateral symmetry in these parameters was recorded and the data were statistically analyzed. RESULTS The study revealed variable prevalence of multiple roots and canals in maxillary and mandibular canines. Ahmed's and Vertucci's type I canal configuration was predominantly observed. Notably, significant bilateral symmetry was noted in root and canal numbers, and canal configurations. CONCLUSIONS The most common configuration of permanent canines was a single root and canal, usually adhering to Ahmed's and Vertucci's type I classification. Mandibular canines showed a higher incidence of two canals than two roots. The extent of bilateral symmetry, especially in mandibular canines, could provide valuable insights for better contralateral tooth treatment planning.

Influence of Post Angulation between Coronal and Radicular Segment on the Fracture Resistance of Endodontically Treated Teeth.

INTRODUCTION: The objectives of coronal restoration in the Endodontically Treated Teeth (ETT) include rehabilitation of aesthetics, function and prevention of coronal leakage. The long axis of root and the coronal segment in the maxillary anterior teeth varies according to the occlusal scheme. The restorative dentist is required to fabricate the post angulation in compatibility to contour of the adjacent teeth. AIM: To evaluate the influence of the angle between the long axes of core facial surface and the radicular segment of the post on fracture resistance of ETT. MATERIALS AND METHODS: Total of 30 maxillary intact canines was root canal treated, sectioned 2 mm above the CEJ. The custom made nickel-chromium endodontic posts were fabricated using direct method. The samples were divided among three groups of 10 each. The angle between coronal segment and radicular segment of post in Group-I, Group-II, Group-III were 5°, 10° and 15° respectively. The teeth samples were cemented with full veneer metal crown and tested under universal testing machine. The static load at the angle of 130° was applied until the fracture to record the fracture strength. The obtained data was statistically analysed with ANOVA and Tukey post-hoc test. RESULTS: The Group-III showed the highest fracture strength with 666.15 N. The Group-II and Group-I recorded the mean fracture strength at 443.37 N and 276.74 N respectively. CONCLUSION: The endodontic post with higher angle between the long axis of facial surface and radicular segment long axis had the positive correlation to the fracture strength in ETT.