Shaping potential of manual NiTi K-File and rotary ProTaper and analyzing the final outcome of shaped canals using CT.

AIM: To assess and compare the shaping potential of manual NiTi K-files and Rotary ProTaper instruments in narrow canals using CT. OBJECTIVE: To assess the shaping potential of manual NiTi K-files and Rotary ProTaper and analyzing the final outcome of shaped canals using CT and determining different variables, like • Working time • Change in volume • Change in cross-sectional area. MATERIALS AND METHODS: From a pool of fifty freshly extracted permanent maxillary molars (1st and 2nd), 30 were selected with curvatures (20 to 40°) (Schneider 1971). Tissue fragments and calcified debries were removed from the teeth by scaling. The teeth were then stored in normal saline until used. All the mesiobuccal canals were scanned by CT to obtain preinstrumented images. Teeth were scaled and stored in normal saline. This study was divided in two groups with 15 samples each. GROUP I (PROTAPER ROTARY): Canals were instrumented with Protaper Rotary instruments using crown down technique according to manufacturer's instructions. GROUP II (NITI K-FILE): Were instrumented by NiTi K-files using step back technique with a quarter turn/pull motion. EVALUATIONS OF WORKING TIME: Comparative evaluations of working time was done for both the experimental groups. CT ANALYSIS AND MEASUREMENTS: The samples were analyzed and evaluated for: • Postinstrumentation change in volume. • Postinstrumentation change in cross-sections area. RESULT: From the observations and statistical analysis carried out in this study, it was found that: There was a statistically significant difference between all the parameters judged for the present study that is: 1. Instrumentation with ProTaper Rotary system took significantly less time than instrumentation with manual NiTi K-file. 2. Change in the canal volume following instrumentation with ProTaper Rotary was significantly greater than that produced by manual NITi K-file. 3. a. Change in cross-section area at 2 and 3 mm from the apex was significantly greater with manual NiTi K-file as compared to ProTaper Rotary. b. Change in cross sections at 4.5, 6 and 7.5 mm from the apex with ProTaper Rotary was significantly greater than that produced by manual NITi K-file. CONCLUSION: This clearly establishes that there is a drastic difference in the shaping ability of manual and Rotary NiTi instruments used with step back and crown down technique respectively with the rotary instrumentation being faster and producing greater changes in the canal anatomy.

To compare the continuous and intermittent irrigation method on the removal of dentin debris from root canals and to evaluate the dynamics of irrigant flow using computational fluid dynamics.

AIM: This study aimed to compare the efficiency of continuous and intermittent irrigating methods on the removal of dentin debris from the simulated grooves and to evaluate the dynamics of irrigant using computational fluid dynamics (CFD). METHODOLOGY: Seventy-five extracted human permanent maxillary canines were selected. Access cavities were made, working length was determined, and canals were prepared by crown down technique. The teeth were split longitudinally and standard groove 2.0 mm in length was made in split halves and each groove was filled with dentin debris and the images were taken under a microscope (E200). The halves were re-assembled and divided into five groups based on different irrigation methods. Group 1: ultrasonic Irrigation with continuous flow for 3.0 min; Group 2: ultrasonic irrigation with continuous flow for 1.5 min; Group 3: ultrasonic irrigation with intermittent flow for 3.0 min; Group 4: ultrasonic irrigation with the intermittent flow for 1.5 min; and Group 5: syringe irrigation for 1 min. The root halves were again separated and re-evaluated for debris elimination after the irrigation protocol for all the groups separately. The effect of time and method of passive ultrasonic irrigation were compared. For the computational fluid analysis, a GAMBIT 2.2 (Ansys) software was used for mesh construction. FLUENT 6.2 (Ansys) software was used to set the boundary conditions and reconstruction of the canal; flow patterns and turbulence were graphically constructed. RESULTS: The continuous irrigation methods were better at debris removal than intermittent irrigation flow methods. The CFD showed that the turbulence of flow of irrigant was dependent on the inlet velocity and pressure of the irrigant. CONCLUSION: Debris removal from the simulated grooves was better with continuous irrigation compared with intermittent irrigation. CFD study revealed that the turbulence that was affected by the velocity and pressure of the irrigant introduced and is a variable entity.

Influence of the glide path on various parameters of root canal prepared with WaveOne reciprocating file using cone beam computed tomography.

BACKGROUND: Nickel-titanium (NiTi) rotary instrumentation carries a risk of fracture, mainly as a result of flexural (fatigue fracture) and torsional (shear failure) stresses. This risk might be reduced by creating a glide path before NiTi rotary instrumentation. The aim of this study was to compare various root canal parameters with the new WaveOne single-file reciprocating system in mesial canals of mandibular molars with and without glide path using cone beam computed tomography (CBCT). MATERIALS AND METHODS: One hundred mandibular molar teeth with canal curvature between 20° and 30° were divided into two groups of 50 teeth each. In Group 1, no glide path was created, whereas in Group 2, a glide path was created with PathFiles at working length (WL). In both groups, canals were shaped with WaveOne primary reciprocating files to the WL. Canals were scanned in a CBCT unit before and after instrumentation. Postinstrumentation changes in canal curvature, cross-sectional area, centric ability, residual dentin thickness, and the extent of canal transportation were calculated using image analysis software and subjected to statistical analysis. Data were analyzed using Student's t-test and Mann-Whitney U-test (P < 0.05). RESULTS: The mean difference of root canal curvature, cross-sectional area, centric ability, and residual dentin thickness increased, whereas it reduced significantly for canal transportation in Group 2. CONCLUSION: WaveOne NiTi files appeared to maintain the original canal anatomy and the presence of a glide path further improves their performance and was found to be beneficial for all the parameters tested in this study.

Comparative Evaluation of Three Different Obturating Techniques Lateral Compaction, Thermafil and Calamus for Filling Area and Voids Using Cone Beam Computed Tomography: An Invitro study.

INTRODUCTION: The success of root canal treatment depends upon the proper sealing of root canal system. Improper apical seal leads to the microleakage which can be prevented by proper obturation technique. AIM: To compare the quality of three different root canal obturation techniques: lateral compaction, Thermafil and Calamus by using cone beam computed tomography. MATERIALS AND METHODS: A total of 30 central incisors were selected. Biomechanical preparation was done by Reciproc file no 25. Teeth were divided into 3 groups of 10 teeth each according to the obturation technique i.e. Calamus, Thermafil and lateral compaction. Cone beam computed tomography was used to measure filling area and voids at coronal, middle and apical third of the root canal after obturation by different techniques. Data was statistically analysed by One-Way Anova and multiple comparison of Tukey HSD tests. RESULT: The maximum amount of obturating material was observed in Calamus group followed by Thermafil and lateral compaction. Minimum voids were seen in obturation by Calamus technique. CONCLUSION: Within the limitations of this study, it can be concluded that Calamus may be a good obturation technique.

Modifications in Canal Anatomy of Curved Canals of Mandibular First Molars by two Glide Path Instruments using CBCT.

BACKGROUND: The creation of glide path reduces the risk of instrument breakage. Glide path is created before using NiTi rotary instrumentation Aim: This study compared the changes in the root canal anatomy after creation of glide path using Path Files (PF) and V Glide Path 2 (VGP2) using Cone Beam Computed Tomography (CBCT). MATERIALS AND METHODS: Hundred extracted mandibular first molars with curved mesial roots, curvature angles ranging within 20-30 degrees were assigned into two groups (n = 50 each). Glide path was prepared using PF (Group I) and VGP2 (Group II). CBCT images were obtained before and after instrumentation. The technical outcomes were compared at 0, 1, 2, 3, 5 and 7mm intervals. The data was analyzed using t-test and Chi-square test. RESULT: There was a statistical difference between the root canal curvatures and working time between the two groups (p < 0.05). Canals transported towards the distal side in Group II but there was a slight mesial transportation in Group I at 0mm. Group I exhibited a better centric ability except at 1mm interval (p > 0.05). The changes in the volume were statistically significant only at 2mm interval (p < 0.05). The difference in the cross sectional area was not statistically significant at any interval (p > 0.05). CONCLUSION: Within the limits of this study the rotary Nickel Titanium Path Files appeared to be suitable instruments for safe and easy creation of glide path.

Endodontic management of mandibular third molar with three mesial roots using spiral computed tomography scan as a diagnostic aid: a case report.

Aberrant root canal anatomy is diagnostically and clinically challenging for clinicians. The most common root canal configuration of human molars is 2 roots and 3 canals, but various combinations may still exist. Third molars are known to have the most unusual anatomy among human teeth. Restorative, prosthetic, and orthodontic considerations often require endodontic treatment of third molars in order for them to be retained as functional components of the dental arch. The present case report demonstrates unusual root canal morphology of the mandibular third molar. Roentgenographic examination, which included spiral CT scan, revealed 3 separate mesial roots in tooth #48 with 3 independent canals and 3 canal orifices, indicating an endodontic rarity. The present case report puts impetus on exploration of additional canals using advanced diagnostic aids, such as spiral computed tomography, which can have a huge impact on the successful outcome of endodontic therapy.