Rotary System Research Articles

Micro-Computed Tomographic Evaluation of the Shaping Ability of Vortex Blue and TruNatomyTM Ni-Ti Rotary Systems

Micro-Computed Tomographic Evaluation of the Shaping Ability of Vortex Blue and TruNatomyTM Ni-Ti Rotary Systems

CLAMPING TOOLS PRINTED FROM ONYX AND USED IN INDUSTRIAL MANUFACTURING PROCESS

The publication verifies the theoretical possibilities of reducing production costs and production time for machine clamping jaws. The primary idea involves maintaining the design for conventional production while replacing the steel alloy 1.7225 with the ONYX plastic composite material reinforced with carbon fiber. The study was first verified computationally and then experimentally in industrial operations. The results of the study were recorded and carefully analyzed. The usability of the ONYX composite, in conjunction with carbon fiber, does not support its use in industrial operations. Although the rotary system was significantly lighter, the clamping elements exhibited relatively high elasticity values. Therefore, the results were unsatisfactory but highly beneficial for the practice and usability of plastic composites.

Effect of Cryotherapy and Occlusal Reduction on Postoperative Endodontic Pain in Mandibular First Molars with Symptomatic Apical Periodontitis: A Prospective, Parallel, Double-Blinded Randomized Controlled Trial.

This study aimed to compare the intensity of postoperative pain following the final rinse using cold saline compared with room temperature saline and occlusal reduction. A prospective, parallel, double-blinded randomized controlled trial was conducted on 69 first mandibular molars diagnosed with symptomatic irreversible pulpitis and symptomatic apical periodontitis. Single-visit root canal treatment was performed; access cavity preparations and chemomechanical preparations were carried out using the ProTaper Gold rotary system under copious irrigation using 3% sodium hypochlorite and 17% EDTA. The patients were divided into three groups (n = 23): control group: room temperature saline (25°C) final rinse without occlusal reduction; cryotherapy group: cold saline (2.5-4°C) final rinse without occlusal reduction; and occlusal reduction group: room temperature saline with occlusal reduction. Pain scores were recorded using the visual analog scale preoperatively and postoperatively via telephone at 6, 24, 48, 72 hours, and 7 days intervals. Age data were analyzed using one-way analysis of variance followed by Tukey's post hoc test. Pain score data were analyzed using Kruskal-Wallis' test followed by Dunn's post hoc test for intergroup comparisons and Friedman's test followed by Nemenyi's post hoc test for intragroup comparisons. Correlations were analyzed using Spearman's rank-order correlation coefficient. The significance level was set at p < 0.05 within all tests. Cryotherapy reduced postoperative pain compared with the control group with a statistically significant difference at 24 hours only (p = 0.016). At other intervals, no statistically significant difference in pain score was measured between all three groups (p > 0.05). After 7 days, all patients recorded a zero pain score. Cryotherapy was as effective as the occlusal reduction in reducing postoperative pain in cases of symptomatic irreversible pulpitis with symptomatic apical periodontitis, significantly more than the control group.

A supervised machine learning model to select a cost-effective directional drilling tool

With the increased directional drilling activities in the oil and gas industry, combined with the digital revolution amongst all industry aspects, the need became high to optimize all planning and operational drilling activities. One important step in planning a directional well is to select a directional tool that can deliver the well in a cost-effective manner. Rotary steerable systems (RSS) and positive displacement mud motors (PDM) are the two widely used tools, each with distinct advantages: RSS excels in hole cleaning, sticking avoidance and hole quality in general, while PDM offers versatility and lower operating costs. This paper presents a series of machine learning (ML) models to automate the selection of the optimal directional tool based on offset well data. By processing lithology, directional, drilling performance, tripping and casing running data, the model predicts section time and cost for upcoming wells. Historical data from offset wells were split into training and testing sets and different ML algorithms were tested to choose the most accurate one. The XGBoost algorithm provided the most accurate predictions during testing, outperforming other algorithms. The beauty of the model is that it successfully accounted for variations in formation thicknesses and drilling environment and adjusts tool recommendations accordingly. Results show that no universal rule favors either RSS or PDM; rather, tool selection is highly dependent on well-specific factors. This data-driven approach reduces human bias, enhances decision-making, and could significantly lower field development costs, particularly in aggressive drilling campaigns.

Vibration analysis of push-the-bit rotary steerable bottom hole assembly

With the development of oil and gas fields to the deep-sea, the rotary steerable system is widely used. Downhole vibration is an important factor affecting the performance of rotary steerable system. Currently, the lack of research on vibration during operation of rotary steerable system has affected the development of deep-sea oil and gas field development technology. In this paper, the dynamic model of the push-pull rotary steerable system is established based on the similarity principle. The model includes Bit-rock interaction model, Drillstring-borehole contact model and guiding force model of rotary steerable system, the trajectory and vibration of drill bit under different guiding forces are simulated. Then, the actual drilling experiment of the full-scale Push-The-Bit Rotary Steerable System (PTB-RSS) in the horizontal section is carried out. The acceleration and speed signals of the push-pull rotary steerable system in the process of applying guiding force are collected and verified with the calculation results of the dynamic model. It is found that the vibration frequency and amplitude of the Bottom Hole Assembly (BHA) gradually increase with the increase of the guiding force of the PTB-RSS during the drilling stage, which induce high-frequency torsional vibration to a certain extent. In addition, the dynamic simulation shows that when the guiding force of the rotary steerable system is increased to a certain extent, the vibration of the BHA gradually stabilizes, but the vibration amplitude does not decrease.

Comparative Micro-CT Analysis of Minimally Invasive Endodontic Systems Using 3D-Printed Replicas and Natural Teeth.

(1) Background: This study aimed to compare the shaping abilities of modern minimally invasive endodontic systems using natural teeth and 3D-printed resin replicas. These replicas offer a standardized approach for studying root canal preparation while eliminating the variability and scarcity of natural teeth. (2) Methods: Eleven mandibular molars with Vertucci class IV anatomy and their 3D-printed replicas (n = 132 canals) were scanned using micro-CT before and after preparation with six rotary systems. Shaping abilities were assessed by comparing volume, surface area, and unprepared areas between natural teeth and their 3D replicas, focusing on the apical third. Statistical analysis included the Shapiro-Wilk test to assess data normality and ANOVA and t-tests to compare different endodontic systems. (3) Results: Both qualitative and quantitative analyses revealed high similarity between natural teeth and 3D replicas. No significant differences in volume or surface area were found except in the apical third, where 3D replicas showed slightly larger increases in volume. (4) Conclusions: 3D resin replicas closely mimic natural teeth and provide a practical tool for assessing the shaping abilities of endodontic systems. This study demonstrates that 3D-printed models are suitable for endodontic research, offering a standardized and accessible alternative to natural teeth.

ProTaper Ultimate: The Evolution of Rotary Systems and Their Clinical Applicability

ProTaper Ultimate: The Evolution of Rotary Systems and Their Clinical Applicability

Post-Space Disinfectants With Sodium Hypochlorite and Methylene Blue Loaded in Silver and Quartz Nanoparticles Activated by Photodynamic Therapy. A SEM Analysis.

Post-space disinfectants methylene blue loaded with silver (Ag) and Quartz nanoparticles (NPs) and MB alone activated by photodynamic therapy (PDT) on the survival of Enterococcus faecalis, smear layer (SL) removal efficacy, and extrusion bond strength (EBS) of fiber posts to canal dentin. Hundred mandibular premolars underwent root canal treatment using the rotary ProTaper system. The canals were obturated and post-space was prepared up to a length of 8 mm, maintaining a 5 mm seal. To assess antibacterial efficacy E. faecalis were inoculated in the canal (n = 20). The samples were then randomly allocated into four groups according to the canal disinfectant used to sterilize the canals. Group 1: 2.5% NaOCl+17% EDTA, Group 2: MB-PDT, Group 3: MB@QP-PDT, and Group 4: MB@AgNP-PDT (n = 25). SEM analysis was conducted on five samples from each disinfectant group to assess the removal of the SL. Survival rates were calculated (n = 5 from each group). Glass fiber post (GFP) was cemented to the root dentin of the remaining samples followed by artificial aging. Sectioning of the specimens was performed in all three-thirds of the canals. PBS was assessed followed by failure evaluation. ANOVA and Tukey post hoc test were used to compare the E. faecalis survival rate and PBS of fiber post among different investigated groups. Group 4 (MB@AgNP-PDT) treated canals exhibited the minimum survival rate (0.30 ± 0.04 CFU/mL) of E. faecalis and maximum PBS. However, the highest survival rate and minimum bond strength of GFP were observed in Group 1 (NaOCl+17% EDTA) and Group 2 (MB-PDT) treated teeth respectively. The highest SL removal was recorded in the coronal section of the samples of Group-4 disinfected with MB@AgNP-PDT. The lowest removal of SL was recorded in Group 2 samples sterilized with MB-PDT at apical one-third. Silver nanoparticles when utilized as nano-carriers to enhance the efficiency of MB activated by PDT, have been shown to exhibit the highest antimicrobial potency, improved capacity for SL removal and improved PBS.

Control strategies for mitigating torsional and axial vibrations in rotary oilwell drilling systems

Abstract This paper examines a nonlinear dynamics model to explore the significant factors influencing the coupled torsional-axial vibrations of a drill string. The primary focus lies in effectively modeling, analyzing, and controlling both torsional and axial vibrations occurring in a rotary oil well drilling system. The model employed incorporates a wave equation with a damping term (PDE) connected to an ordinary differential equation (ODE) through a nonlinear function representing the interaction between the drill bit and the rock. We proceed to establish the well-posedness of the coupled PDE-ODE in an appropriate functional space. As a PDE-ODE coupled system, we specifically investigate the stability problem concerning the velocity at the bottom extremity, considering both the presence and absence of the damping term in the wave PDE. To address this, we propose a systematic method based on a Lyapunov approach for designing feedback controllers. These controllers ensure system stability and effectively suppress harmful vibrations.

Design of Integrated Dual Spiral Spring and Rotary Hydraulic Damper System for Torsional Vibration Damping in Pesticide Sprayer Gearbox

Design of Integrated Dual Spiral Spring and Rotary Hydraulic Damper System for Torsional Vibration Damping in Pesticide Sprayer Gearbox

Online Self-Learning-Based Raw Material Proportioning for Rotary Hearth Furnace and Intelligent Batching System Development

With the increasing awareness of environmental protection, the rotary hearth furnace system has emerged as a key technology that facilitates a win-win situation for both environmental protection and enterprise economic benefits. This is attributed to its high flexibility in raw material utilization, capability of directly supplying blast furnaces, low energy consumption, and high zinc removal rate. However, the complexity of the raw material proportioning process coupled with the rotary hearth furnace system’s reliance on human labor results in a time-consuming and inefficient process. This paper innovatively introduces an intelligent formula method for proportioning raw materials based on online clustering algorithms and develops an intelligent batching system for rotary hearth furnaces. Firstly, the ingredients of raw materials undergo data preprocessing, which involves using the local outlier factor (LOF) method to detect any abnormal values, using Kalman filtering to smooth the data, and performing one-hot encoding to represent the different kinds of raw materials. Afterwards, the affinity propagation (AP) clustering method is used to evaluate past data on the ingredients of raw materials and their ratios. This analysis aims to extract information based on human experience with ratios and create a library of machine learning formulas. The incremental AP clustering algorithm is utilized to learn new ratio data and continuously update the machine learning formula library. To ensure that the formula meets the actual production performance requirements of the rotary hearth furnace, the machine learning formula is fine-tuned based on expert experience. The integration of machine learning and expert experience demonstrates good flexibility and satisfactory performance in the practical application of intelligent formulas for rotary hearth furnaces. An intelligent batching system is developed and executed at a steel plant in China. It shows an excellent user interface and significantly enhances batching efficiency and product quality.

Evaluation of the Root Canal Centering Ratio and Canal Transportation Associated With Three Rotary File Systems Using Cone Beam Computed Tomography (CBCT) Analysis.

Aim The aim of the present study was to evaluate the in vitro comparative assessment of root canal centering ratio and canal transportation associated with ProTaper Universal (PTU) (Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Next (PTN) (Dentsply Maillefer, Ballaigues, Switzerland), and ProTaper Gold (PTG) (Dentsply Tulsa Dental Specialties, Tulsa, OK, USA) rotary file systems, with or without glide-path preparation, using cone beam computed tomography (CBCT) analysis. Materials and methods A total of 120 mesial roots of extracted human mandibular first molar teeth were collected and randomly divided into three groups (n = 40) depending on the type of rotary file system used for mesiobuccal root canal instrumentation: Group 1: PTU, Group 2: PTN, and Group 3: PTGrotary file systems. Each group was further divided into two Sub-groups (a and b) with 20 specimens, depending on whether glide-path preparation was performed using the ProGlider (PG) file (Dentsply Maillefer, Ballaigues, Switzerland). Before the root canal instrumentation, mesiobuccal root canals of all specimens were first scanned using the NewTom Go CBCT machine (Cefla S.C., Imola, Italy), and all root canals were then instrumented according to their groups and sub-groups. All rotary files were used according to their manufacturer's guidelines. Post-instrumentation, CBCT images of all specimens were taken with the same exposure parameters as those used in pre-instrumentation CBCT imaging. The distance between the external root surface and the internal canal wall was measured in both bucco-lingual and mesio-distal planes at 3 mm, 5 mm, and 7 mm levels of the mesiobuccal root canal of all specimens, comparing the pre-instrumentation and post-instrumentation CBCT scans for the evaluation of canal centering ratio and canal transportation using NewTom NNT software (Cefla S.C., Imola, Italy). Data were analyzed using one-way analysis of variance (ANOVA), multiple pairwise Tukey post-hoc tests, and Student's t-tests; a p-value ≤ 0.05 was considered statistically significant. Results Canal centering ratio was significant bucco-lingually and mesio-distally at 3 mm and 5 mm levels between Groups 1a, 1b, and 3a, 3b (p < 0.05). However, at 7 mm bucco-lingually, a significant difference was observed between groups 3a and 3b, and mesio-distally between Groups 2a and 2b (p < 0.05). Canal transportation was significantly bucco-lingually at 3 mm, 5 mm, and 7 mm levels between Groups 3a and 3b (p < 0.05). However, mesio-distally, no statistically significant difference (p > 0.05) was seen between the groups at all three levels of the root canal. Conclusion The use of the PG/PTN rotary file system showed the maximum canal centering ratio at all three levels of the root canal compared to the PTU and PTG rotary file systems, whether used with or without a glide-path. The PG/PTN rotary file system showed the least canal transportation at the 3 mm level, while at the 5 mm and 7 mm levels, the PG/PTU rotary file system showed the least canal transportation.

Comparative evaluation of remaining dentin thickness and root canal transportation in curved canals with newer nickel–titanium single and multiple rotary file systems: A cone-beam computed tomography study

Abstract Context: The purpose of this study was to evaluate and compare the remaining dentin thickness and root canal transportation of WaveOne GOLD, XP-endo Shaper, and GenEndo file systems to assess their performance in curved canals using cone-beam computed tomography (CBCT) imaging. Materials and Methods: Seventy-five extracted maxillary first molars were selected with a curvature ranging between 15° and 30°. The samples were allocated into three groups (n = 25) and shaped using WaveOne GOLD, XP-endo Shaper, and GenEndo files. CBCT images were captured before and after instrumentation. Statistical Analysis: The remaining dentin thickness and root canal transportation were measured at 3, 5, and 7 mm from the apex in both mesiodistal and buccolingual directions. The data were statistically analyzed using one-way ANOVA followed by Tukey’s post hoc test. Results: GenEndo file system demonstrated greater preservation of remaining dentin thickness and resulted in less root canal transportation compared to the WaveOne GOLD and XP-endo Shaper systems across all three levels. Conclusions: GenEndo file system which comprises multiple files has removed less amount of dentin and canal transportation when compared to single file systems, i.e., WaveOne GOLD and XP-endo Shaper file systems.

Cutting Efficiency and Cleaning Ability of Three Different Nickel Titanium Rotary Systems (An In vitro study)

Cutting Efficiency and Cleaning Ability of Three Different Nickel Titanium Rotary Systems (An In vitro study)

Eksik Tahrikli Döner Ters Sarkaç Sisteminin Yukarı Yükseltilmesi için Enerji Tabanlı Doğrusal Olmayan Kontrol Algoritması ve Deneysel Doğrulaması

Bu çalışmada, döner ters sarkaç sistemi hareketli koluyla sınırlı bir bölge içinde, salınımı kontrol edilerek ve sarkaç enerjisi artırılarak, kararlı denge noktasından kararsız denge noktasına çıkarılması hedeflenmektedir. Döner ters sarkaç sisteminin doğrusal olmayan modeli ve denge noktalarındaki doğrusal modelleri verildikten sonra sarkaç yukarı yükseltme algoritması tanıtılmaktadır. Yukarı yükseltme algoritması, sarkaç salınırken belli noktalarda kol yardımıyla sarkaca enerji yüklemesine dayanmaktadır. Burada kol ivmelendirilmesi sabit bir ivme ile hareket ettirilmektedir. Yukarı yükseltme işlemindeki algoritma, sarkacın hızının en fazla olduğu yere yani kararlı denge noktasına ilerlerken ve periyodunu tamamlarken devreye girmektedir. Bu analizler hesaplanmış sınırlar dikkate alınarak yapılmaktadır. Sarkacın yukarı yükselmesi gerçekleştiğinde doğrusal model üzerinden elde edilmiş temel bir tam durum geri beslemeli kontrolcü devreye girmektedir ve sarkacı kararsız denge noktasında tutmaktadır. Böylece, anahtarlamalı bir kontrol yapısı elde edilmektedir. Önerilen kontrol algoritmasının doğrulaması için önerilen algoritma bir döner sarkacı üzerinde gerçek zamanlı olarak test edilmiştir. Farklı kol ivmelendirme değerleri ile elde edilen karşılaştırmalı sonuçlar sunulmuştur. Kol ivmesi ±32 rad/s2’den ±64 rad/s2’ye çıkarıldığında sarkacın yukarı yükselme süresi yaklaşık 9 s’den 5 s’ye düşmektedir. Bu sonuçlar, önerilen algoritmanın deneysel başarısını göstermektedir.

Probabilistic Analysis of Orbital Characteristics of Rotary Systems with Centrally and Off-Center Mounted Unbalanced Disks

Rotor dynamics plays a crucial role in the performance and safety of rotating machinery, with disk position and unbalance significantly impacting system behavior. This study investigates the dynamic characteristics of two rotor configurations: a centrally mounted unbalanced disk (Rotor05un) and an off-center unbalanced disk (Rotor025un). Using numerical simulations and Monte Carlo analysis, we examined critical speeds and orbital patterns for both configurations. Probability distributions of shaft orbital positions revealed distinct patterns for each configuration. Quantile analysis revealed approximate linear trends for Rotor025un, suggesting higher system stiffness and more predictable behavior near critical speeds. Cross-sectional analyses of the orbits provided insights into the complex interactions between disk position, gyroscopic effects, and system natural frequencies. These findings provide valuable insights for rotor system design, particularly for applications with non-ideal mass distributions. The study goes beyond traditional critical speed analysis to examine orbital patterns and point on orbit occurrence from a probabilistic perspective. Based on the simulation of the orbits, an orbital is determined that allows the probability of the shaft occurring at the analyzed distance from the origin to be determined. The paper also offers insights into the complex interaction behavior of chosen rotor configurations and highlights the importance of considering disk position in predicting and optimizing rotor dynamic behavior, contributing to the development of more robust and efficient rotating machinery.

Precession of a rotor with a different number of discrete radial elastic damping supports

A design model of a rotary system in the form of a cantilevered flexible shaft with a massive unbalanced disk at the free end is considered. In the plane of rotation of the disk, point elastically damped supports are discretely located with a clearance, stabilizing the vibrations of the rotor in the supercritical zone. With the help of the introduced precession indicator, the type and direction of the precession of the rotor during interaction with the supports is analyzed. The influence of a different number of supports on the evolution of the rotor precession in the supercritical zone after the Poincare-Andronov-Hopf bifurcation is investigated. The effect of the clearance and eccentricity of the disk mass at the contact of the disk with the supports on the precession of the rotor is analyzed.

Comparative evaluation of pediatric endodontic rotary file systems to bending and torsion tests: A finite element analysis

Background and objectiveThe introduction of Paediatric NiTi instruments has transformed the field of paediatric endodontics. However, no studies are available on the mechanical behaviour of these files, wherein Finite Element Analysis (FEA) was found to play a major role. The objective of this study is to evaluate the mechanical behavior of three commercially available pediatric endodontic rotary file systems to bending and torsion stress analysis test through Finite Element Analysis (FEA). MethodsA Finite Element Analysis study was performed on three commercially available pediatric endodontic rotary files (Pro AF baby, Kedo SG and Neoendo pedoflex) available for cleaning and shaping the narrow root canals of the deciduous teeth to bending and torsion tests with the boundary conditions according to ISO 3630-1 specifications. ResultsIn the bending analysis, Pro AF baby files were found to withstand the complete bending tests without yielding with a maximum von Mises stress of 1366 MPa, and Kedo SG, Neoendo Pedoflex file exhibited maximum von Mises stress of 2296 MPa, 1971 MPa. Under torsion tests Kedo SG exhibited maximum stress distribution, while Neoendo Pedoflex and Pro AF baby files exhibited similar stress distribution. ConclusionPro AF baby file effectively withstood the rigorous 45 -degree bending examination without experiencing yielding, while Kedo SG file exhibited higher flexibility. Under torsional resistance test, all the three instruments exhibited similar stress distribution under the yield limit. In summary, the mechanical behaviour (bending and torsion) of pediatric rotary file systems were influenced by design of the files.

Comparative Evaluation of Effectiveness of Rotary and Hand File Systems in Terms of Quality of Obturation and Instrumentation Time among Primary Teeth: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

This systematic review and meta-analysis aimed to answer the following focused question: Are rotary file systems more effective than hand file systems in terms of the quality of obturation and instrumentation time among primary teeth? The inclusion criteria comprised studies that compared the effect on quality of obturation and instrumentation time among primary teeth after using rotary and hand file systems for biomechanical preparation of the root canals. This review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The searched databases included Medline (via PubMed), EBSCO, and Google Scholar. Articles published from January 2000 to December 2021, but only in English, were included. The search resulted in 8,003 published studies. After the removal of duplicate studies and full-text analysis, 9 studies were selected for systematic review, and 8 were selected for meta-analysis. Overall, the results demonstrated the promising effects of rotary file systems in reducing instrumentation time and improving obturation quality compared to hand files. Within the limitations of this review, it can be asserted that rotary file systems are superior to hand files in primary teeth for pulpectomy procedures. Rotary files, a more recent technique, are more efficient than traditional hand files in lowering the time required for instrumentation. Additionally, they provide superior obturation quality in primary molars, making them particularly beneficial for pediatric patients. Gala UP, Kalaskar R, Vinay V, et al. Comparative Evaluation of Effectiveness of Rotary and Hand File Systems in Terms of Quality of Obturation and Instrumentation Time among Primary Teeth: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Int J Clin Pediatr Dent 2024;17(8):962-969.

Evaluation and Comparison of Dentin Thickness, Centering Ability, Canal Transportation, and Instrumentation Time of Pro AF Baby Gold and Pedoflex Files in Primary Root Canals Using a Cone Beam Computed Tomographic Analysis: An In Vitro Study.

Pediatric rotary systems have the advantage of improved canal centricity and conservative canal preparation with better obturation quality. Pro AF Baby Gold and Pedoflex files are two exclusive pediatric rotary file systems that were introduced in recent times. The aim of the present study is to compare and evaluate the dentine thickness, centering ability, canal transportation, and instrumentation time of Pro AF Baby Gold and Pedoflex files using cone beam computed tomography (CBCT). A total of 40 extracted human primary molar teeth with a minimum 7 mm root length were included in the study and randomly divided into two groups: group I, Pro AF Baby Gold; group II, Pedoflex files. Teeth were imaged preoperatively with CBCT, then root canal preparation was done in both groups with respective files, followed by postoperative CBCT imaging to evaluate the dentin thickness, centering ability, and canal transportation of both groups. Instrumentation time was noted using a stopwatch. There is a statistically significant difference in the instrumentation time; Pedoflex took a shorter time when compared to Pro AF Baby Gold files. Regarding canal transportation, there was no significant difference between the two files, with Pedoflex showing a better value than the other files. Regarding centering ability, there was no significant difference between the two files, with Pro AF Baby Gold having a better value than the other files (p < 0.001). From the findings of our present study, it was found that both systems were able to effectively shape curved root canals in terms of canal transportation and centering ability. Busi S, PJ N, Deoghare A, et al. Evaluation and Comparison of Dentin Thickness, Centering Ability, Canal Transportation, and Instrumentation Time of Pro AF Baby Gold and Pedoflex Files in Primary Root Canals Using a Cone Beam Computed Tomographic Analysis: An In Vitro Study. Int J Clin Pediatr Dent 2024;17(8):892-897.