Introduction and background
The preservation of primary teeth is essential not only for functional and esthetic purposes but also for guiding the eruption of permanent successors and maintaining arch integrity [1]. Pulpectomy remains a widely accepted treatment modality for non-vital primary teeth, particularly in cases of extensive carious involvement or trauma [2]. Traditionally, root canal instrumentation in pediatric dentistry has relied on manual stainless steel files. While effective, these manual instruments have notable drawbacks. They are time-consuming, are technique-sensitive, and can lead to prolonged chairside time and discomfort, which is often poorly tolerated by young patients [3]. Nickel-titanium (NiTi) rotary files, made from a highly flexible metal alloy originally designed for permanent teeth, offer advantages such as improved flexibility, greater efficiency, and better canal centering. However, their initial use in pediatric endodontics was approached with caution due to concerns about anatomical mismatches, procedural safety, and the need for specialized clinician training [4]. Despite these concerns, rotary instrumentation is now increasingly utilized in pediatric dental practice. This trend underscores the need for a critical examination of the technology's evolution, its modifications, and its supporting evidence base.
In the last decade, systematic reviews and meta-analyses have assessed the effectiveness of rotary instrumentation in primary teeth, often comparing these systems to manual or reciprocating alternatives [5]. Several studies have reported that rotary systems reduce instrumentation time and may enhance obturation quality. For instance, reviews by Gala et al. and Faghihian et al. suggest that pediatric rotary files such as Kedo-S and Pro AF Baby Gold demonstrate superior shaping ability and reduced procedural duration compared to manual instrumentation [6,7]. However, these findings warrant cautious interpretation. Many of the existing reviews are based on small sample sizes, rely heavily on in vitro studies with limited clinical translatability, or include studies with heterogeneous methodologies that hinder robust comparisons [8,9]. Moreover, most reviews focus narrowly on select rotary systems and overlook newer designs such as Endogal Kids and Prime Pedo, which limits the comprehensiveness of their findings. There remains a critical gap in understanding how different pediatric rotary systems compare across parameters such as mechanical design, material composition, and clinical outcomes in real-world settings.
Although the literature increasingly supports the role of rotary instrumentation in pediatric endodontics, no existing synthesis has comprehensively mapped all rotary file systems developed specifically for pediatric use between 2000 and 2025. Prior reviews tend to be fragmented, either limited to individual brands or narrowly focused on a single outcome such as shaping efficiency or postoperative pain. Furthermore, many fail to capture the evolution in file design, including heat-treated NiTi metallurgy, pediatric-specific tapers, and shorter working lengths tailored to primary root morphology. The geographic concentration of available research particularly in countries such as India and Egypt also raises concerns regarding generalizability to diverse clinical populations. A broader, more inclusive review is therefore necessary to contextualize technological advancements, evidence trends, and clinical relevance.
This scoping review aims to bridge this gap by cataloging all rotary file systems developed for pediatric endodontics between 2000 and 2025. It further seeks to summarize their technical design features, including taper, length, metallurgy, and motion type. Additionally, it describes the reported outcomes across clinical, in vitro, and imaging-based studies while identifying areas of evidence scarcity and recommending priorities for future research.
Review
Methodology
This scoping review was conducted in accordance with the Joanna Briggs Institute (JBI) framework and reported as per the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) guidelines. A protocol was prospectively registered in the Open Science Framework (OSF) (https://doi.org/10.17605/OSF.IO/3VSMQ), outlining eligibility criteria, data charting methods, and synthesis plans.
Eligibility Criteria
We included primary studies (randomized controlled trials [RCTs], in vitro, ex vivo, observational, and finite element analysis (FEA)/imaging-based analyses), systematic reviews, and narrative reviews published between January 2000 and May 2025 that assessed pediatric rotary endodontic file systems in primary teeth. Studies were included regardless of language and setting. Case reports were included only if they introduced novel file systems not covered in other study designs. Studies exclusively on permanent teeth or adult instrumentation systems were excluded.
Search Strategy
A comprehensive search was conducted across PubMed, Scopus, Web of Science, Embase, Cochrane, and Google Scholar using controlled vocabulary (MeSH) and free-text terms: "pediatric rotary files", "primary teeth endodontics", "NiTi instrumentation", and "pulpectomy". The search was last updated on May 7, 2025. The first 100 hits from Google Scholar were screened for gray literature. Bibliographies of relevant reviews were hand-searched.
Selection and Data Charting
The study selection process was managed using Rayyan, a web-based software designed for systematic reviews. Following automated duplicate removal within the software, two reviewers independently screened the titles and abstracts of the remaining records. Full-text articles were then assessed for eligibility, with any disagreements resolved by consensus. Data were charted using a pre-piloted Excel form capturing study characteristics (author, year, country), file systems evaluated, study design, sample/model, outcomes measured, key findings, and conclusions. Outcome domains were classified as procedural (e.g., instrumentation time, file fracture), radiographic (e.g., obturation quality, canal shaping), microbiological (e.g., colony-forming units [CFUs]), and patient-reported (e.g., post-operative pain, behavior).
Following database searches and removal of 269 duplicates, 155 titles/abstracts were screened, with 135 full texts assessed for eligibility. Ultimately, 111 articles were included in this scoping review. Articles from 2000 to 2025 were included to comprehensively evaluate the evolution and evidence base of pediatric rotary file systems (Figure 1).
Figure 1
PRISMA 2020 flow diagram depicting the study selection process for the scoping review
This PRISMA flow diagram illustrates the identification, screening, and inclusion process of studies for the scoping review on pediatric rotary file systems. A total of 424 records were identified through database searches. After removing 269 duplicates, 155 records were screened. Of these, 135 full-text articles were assessed for eligibility, with 24 excluded based on inclusion criteria. Ultimately, 111 studies were included in the final review.
Synthesis of Results
Results were synthesized descriptively and grouped by study design: in vitro studies, FEA-based studies, clinical studies (RCTs, observational), and review articles. Rotary systems were further categorized by generation, metallurgy, taper, and motion type. Summary tables were created to map available evidence, highlight commonly assessed outcomes, and identify underrepresented file systems.
Critical Appraisal
As per JBI and PRISMA-ScR guidance for scoping reviews, a formal risk of bias (e.g., RoB-2) or GRADE assessment was not performed, as the primary goal was to map the extent of the literature rather than to synthesize a quantitative effect estimate. However, the quality of the evidence was considered during the synthesis of results. Greater weight was given to evidence from studies with higher methodological rigor, such as RCTs and imaging-based analyses using Cone-beam computed tomography (CBCT) or nano-CT.
Results
A total of 111 studies were included in this scoping review, published between 2000 and 2025. These included 26 RCTs, 62 in vitro studies, 2 FEA studies, 19 review articles, and 2 case reports. An updated timeline of pediatric rotary file system introductions (2000-2025) is presented in Figure 2.
Figure 2
Evolution of rotary endodontic file systems from 2000 to 2025.
The figure presents a chronological timeline of key rotary instruments, beginning with generalized systems originally designed for permanent teeth (e.g., ProFile, ProTaper Universal) and transitioning to pediatric-specific innovations such as Kedo-S (2016), Kedo-SG Blue (2018), and Kedo-S Plus (2023). This progression highlights the design evolution in metallurgy, taper, and working length tailored to primary teeth.
While generalized NiTi systems such as ProFile and ProTaper were initially used in pediatric endodontics, the advent of pediatric-specific rotary systems beginning with Kedo-S in 2016 marked a significant shift. The technical specifications of these dedicated pediatric systems, including taper, metallurgy, and motion type, are summarized in Table 1. Disclosure of funding sources was largely absent across the included literature. Of the 111 studies included, only nine (8.1%) provided information on funding. The remaining articles did not report on the presence or absence of financial support for their research.
Table 1
Technical specifications of pediatric-specific rotary file systems introduced from 2016 to 2025.
This table summarizes taper, motion type, metallurgy, and clinical considerations for commonly used pediatric rotary file systems. The information was primarily compiled from previously published reviews, namely Bonzanini et al. [9], Opi [10], and Kameswari et al. [11].
| File System | Year Introduced | Taper (%) | Motion Type | Metallurgy | Clinical Use |
| Kedo-S | 2016 | 4–6% (variable) | Rotary | Conventional NiTi | First pediatric-specific rotary system |
| Kedo-SG | 2017 | Variable | Rotary | NiTi (enhanced) | Improved design over Kedo-S |
| Kedo-SG Blue | 2018 | Variable (4–6%) | Rotary | Heat-treated NiTi (blue) | Greater flexibility for curved canals |
| Prime Pedo | 2018 | Variable | Rotary | NiTi | Designed for efficient canal shaping |
| Pro AF Baby Gold | 2019 | Variable | Rotary | Heat-treated NiTi | High fatigue resistance; good for narrow canals |
| Sani Kid | 2019 | Not reported | Rotary | NiTi | Pediatric file with limited published specs |
| Denco Kids | 2020 | Not reported | Rotary | NiTi | Pediatric adaptation by Denco |
| Baby Blue | 2021 | Variable | Rotary | Heat-treated NiTi | Pediatric file emphasizing stress resistance |
| Endogal Kids | 2022 | 4% | Rotary | NiTi | Short length (16 mm); good for short roots |
| AF Baby | 2022 | 4–6% | Rotary | Heat-treated NiTi | High flexibility; used in curved and narrow canals |
| Kedo-S Square | 2023 | Variable | Rotary | Enhanced NiTi Alloy | Increased fatigue resistance and centering |
| Kedo-S Plus | 2023 | Variable (4–8%) | Rotary | Heat-treated NiTi | Designed for advanced shaping; wider canal use [9-11] |
In Vitro Studies
A total of 62 studies evaluated rotary instrumentation in primary teeth using in vitro or imaging techniques such as CBCT, scanning electron microscopy (SEM), nano-CT, and 3D printing [12-73]. These assessed outcomes such as instrumentation time, shaping ability, centering, debris extrusion, smear layer removal, and microbial reduction (Table 2).
Table 2
Summary of in vitro studies evaluating pediatric rotary endodontic files in primary teeth
This table presents key study characteristics, including author, country, file systems evaluated, study design, sample details, assessed outcomes, and major findings. The table synthesizes in vitro evidence on rotary instrumentation in pediatric endodontics.
2D, two-dimensional; 3D, three-dimensional; BL, buccolingual; CAR, centering ability ratio; CBCT, cone-beam computed tomography; CFU, colony-forming units; EPD, electrophoretic deposition; GO, graphene oxide; LED, light-emitting diode; MD, mesiodistal; NiTi, nickel-titanium; PDL, periodontal ligament; RDT, remaining dentin thickness; SCT, spiral computed tomography; SEM, scanning electron microscopy; TBO, toluidine blue O
| Author (Year) | Country | Study Design | File Systems Evaluated | Sample/Model | Outcome Measures Assessed | Key Findings | Conclusion/Clinical Implication | Remarks |
| Abushanan et al. (2025) [12] | Saudi Arabia | In vitro | Kedo-SG, Neoendo Pedoflex, Vortex Blue | 120 simulated canals | Cyclic fatigue, SEM | Kedo-SG highest fatigue resistance | Kedo-SG comparable to Vortex Blue | Artificial models; lacks clinical realism |
| Chaudhary et al. (2025) [13] | India | In vitro | Kedo-SG Blue, Pro AF Baby Gold, hand K-files | 30 central incisors | Debris extrusion | Rotary files extruded less debris | Rotary may reduce inflammation | Only anterior teeth studied |
| Bai et al. (2024) [14] | India | In vitro | Prime Pedo, DXL-Pro, Hand H/K | 45 molars | Debris extrusion | Rotary extruded less debris | Rotary reduces complications | No microbial or long-term assessment |
| Eskibağlar and İpek (2024) [15] | Turkey | In vitro | Endoart Blue, M3 Blue, AF Baby, Hand | 40 molars (distal roots only) | Apical debris extrusion | AF Baby extruded least debris; rotary < hand | Rotary safer for inflammation control | Single root type; small sample |
| Okasha et al. (2024) [16] | Egypt | In vitro | Manual K-files, Kedo-SG Blue, AF Baby Fanta | 30 extracted primary canines (10 per group) | Cleaning efficacy (SEM), smear layer, debris scores, instrumentation time | Rotary groups (Kedo-SG and Fanta) showed significantly better cleaning and less smear layer than manual K-files. Kedo-SG was faster (1.65 min) than Fanta (1.85 min) and both were faster than K-files (3.09 min). | Rotary systems are more efficient in cleaning and save chair-side time in pediatric endo | Ex vivo resin canal simulation; SEM limited to surface evaluation; lacks bacterial/microbial comparison |
| Amin et al. (2024) [17] | Egypt | In vitro | Kedo-S, M Pro Pedo, ProTaper Gold | 72 extracted primary molars | Cleaning, bacteria, obturation, time | M Pro fastest; ProTaper Gold best obturation | M Pro efficient but obturation suboptimal | Limited to palatal canals; no clinical behavior |
| Surme et al. (2024) [18] | Turkey | In vitro | X-Baby, miniScope, EndoArt Pedo Gold/Blue | 80 simulated curved canals | Cyclic fatigue | EndoArt Pedo Blue highest fatigue resistance | Advanced NiTi files are durable | Simulated canals only; lacks hydration/movement factors |
| El-Desouky et al. (2024) [19] | Egypt | In vitro (CBCT) | Kedo-S, Kedo-SH, Kedo-SG | 60 extracted molars | Canal taper, debris removal | Kedo-SH had best shaping and cleaning | File choice influences clinical success | Radiographic evaluation only; no clinical trial |
| Khalil and Samir (2024) [20] | Egypt | In vitro (CBCT) | K-files, Kedo-S Plus, Hyflex CM, Race Evo | 140 extracted primary molars | Dentin thickness (middle third) | No significant difference among groups | All rotary systems equally effective | Distal roots only; no apical/coronal data |
| Kesri et al. (2024) [21] | India | In vitro | Pedoflex, Kedo-SH, Manual K-files | 45 molars | Cutting efficiency via ink removal | Pedoflex > Kedo-SH > Manual | Pediatric rotary superior for cutting | Cleaning and obturation not studied. India ink lacks biological debris simulation |
| Panja et al. (2024) [22] | India | In vitro (SEM) | Kedo-SG rotary file (NiTi) coated with graphene oxide | 10 NiTi pediatric rotary instruments | Surface topography via SEM, uniformity of GO coating | Graphene oxide coating via EPD showed uniform, continuous, multilayered GO sheets improving surface structure | GO-coated pediatric rotary files exhibit smoother surface morphology, potentially reducing fracture risk | Only surface morphology assessed; no mechanical or clinical testing performed; lacks coating thickness quantification |
| Suresh et al. (2024) [23] | India | In vitro (Nano-CT) | Kedo-S Plus, Kedo-SG Blue, hand K-files | 60 extracted primary mandibular second molars (20/group) | Volumetric change in root canal space (nano-CT based) | Kedo-SG Blue showed the highest canal enlargement (8.85%), followed by Kedo-S Plus (6.14%) and hand K-files (1.24%). Rotary systems had significantly higher canal shaping ability than hand files. | Rotary systems offer superior volumetric preparation in primary teeth; Kedo-SG Blue achieved most uniform shaping | No clinical validation; limited to extracted teeth with wide canals; only volume changes measured—no microbial or obturation outcome considered |
| Vishwanathaiah (2024) [24] | Saudi Arabia | In vitro (CBCT) | Hand K-files, ProTaper, Kedo-SG Blue | 30 extracted human primary second molars (10/group) | Canal volume (pre-/post-instrumentation), obturation volume (CBCT) | Kedo-SG Blue achieved the highest canal volume change post-instrumentation and post-obturation. ProTaper ranked second, followed by hand K-files. All intergroup differences were statistically significant (p = 0.047 to p = 0.001), with Kedo-SG Blue demonstrating the greatest reduction in post-instrumentation canal volume. | Kedo-SG Blue is most efficient in canal preparation and obturation in primary molars compared to ProTaper and hand files | No clinical validation; root curvature not standardized; only mesiobuccal root of second molars assessed; 3D obturation voids not evaluated |
| Eskibağlar and Özata (2024) [25] | Turkey | In vitro (Experimental) | ProTaper Ultimate (PTU), TruNatomy Prime (TRN) | With vs without glide path; with vs without resorption | 80 extracted primary molars (n=10 per group) | Glide path usage significantly reduced apically extruded debris (p<0.001). Presence of resorption significantly increased debris extrusion (p<0.001). File system type (PTU vs TRN) not statistically significant. | Glide path preparation is effective in reducing apical debris extrusion in primary molars. Root resorption increases debris extrusion regardless of file system. TRN and PTU files performed similarly. | While the study effectively isolates the influence of glide path and resorption, its applicability to pediatric clinical practice may be limited by anatomical variability and lack of behavioral context |
| Abdelkafy et al. (2023) [26] | Egypt | In vitro (CBCT-based) | ProTaper Next (regular), AF Baby (Fanta), Kidzo Elephant (Poldent) | 18 root canals (6 per group) from extracted primary molars | Canal transportation and centering ratio at cervical, middle, apical levels (BL and MD directions) | No significant difference in BL direction across groups. In MD direction at cervical level, ProTaper Next showed significantly higher canal transportation than pediatric rotary files. No significant difference in centering ratio in any group. | Pediatric rotary files (AF Baby and Kidzo Elephant) better preserve cervical canal anatomy mesiodistally than ProTaper Next | Small sample size; only CBCT imaging used; clinical correlation and long-term outcomes not studied |
| Fernandes et al. (2023) [27] | Brazil | In vitro | Manual K-files, Manual NiTi (ProDesign M), Rotary NiTi (ProDesign Logic) | 60 artificial primary molars (stock teeth), 20 per group | Instrumentation time, quality of obturation, taper, flowability | Rotary files (ProDesign Logic) showed significantly shorter prep time (202.3s) than manual NiTi (307.0s) and manual K-files (383.5s); all methods equally effective in shaping and obturation quality | Rotary technique reduces operating time and improves standardization in pediatric root canal prep | Artificial teeth used; not generalizable to clinical anatomy; no microbial or post-operative outcomes evaluated |
| Öz et al. (2023) [28] | Turkey | Ex vivo | Rotary, reciprocating, hand files | Extracted molars | Bacterial reduction (E. faecalis) | All effective; rotary > hand | Rotary improves disinfection | Limited clinical simulation ex vivo only |
| Suresh et al. (2023) [29] | India, Saudi Arabia | In vitro | Hand K-files, Kedo-S Plus, Kedo-SG Blue | 60 extracted primary maxillary central incisors (20 per group) | Apical debris extrusion (Myers and Montgomery model) | Kedo-S Plus: least extrusion (0.6561 mg), Kedo-SG Blue: moderate (0.1021 mg), hand K-file: highest (1.9963 mg) | Rotary files extrude significantly less debris than hand files; Kedo-S Plus performs best | In vitro only; lacks periapical tissue simulation; anterior straight canals only; needs in vivo validation |
| Jome et al. (2023) [30] | India | In vitro | Pedoflex, Pro AF Baby Gold, Kedo-SG Blue | 15 extracted canines | Debris score, smoothness | Pedoflex had best results | Suitable for anterior canals | Very small sample; only anterior teeth used |
| Bal and Aksoy (2023) [31] | Turkey | In vitro (2D Simulation) | Endoart Pedo Smart Gold (EPSG), Endoart Smart Gold (ESG) | 28 simulated curved resin canals | Resin removal (inner/outer), centering ratio, aberration presence | EPSG removed significantly less resin and had superior centering at coronal third; fewer aberrations than ESG | Pediatric-specific rotary file (EPSG) preserved canal anatomy better | Simulated model does not reflect true clinical tissue behavior; heat-softening of resin noted as limitation |
| Yehya et al. (2023) [32] | Egypt | In vitro | Manual K-files, Kedo-S Square, Kedo-S SG Blue | 30 extracted primary maxillary second molars (60 canals) | Cleaning efficacy using India ink removal and clearing technique | Rotary groups (Kedo-S Square and Kedo-S SG Blue) had significantly better cleaning than manual files; no difference between the two rotary groups; apical cleaning least effective | Pediatric rotary files provide better canal cleaning than hand K-files; both systems performed similarly | No instrumentation time measured; apical cleaning not significantly different; India ink may not reflect clinical pulp tissue |
| Gucyetmez Topal et al. (2023) [33] | Turkey | In vitro (3D printed + CBCT) | VDW.ROTATE™, EdgeTaper Platinum™, Manual K-files | 66 CBCT-based resin-printed second primary molars (22 per group) | Canal volume and area change, untouched canal surface area, instrumentation time | No significant difference in canal volume/area among groups. VDW.ROTATE™ had the lowest untouched canal surface area and shortest instrumentation time. EdgeTaper Platinum™ was faster than hand files but less efficient than VDW.ROTATE™. | VDW.ROTATE™ outperformed in shaping ability and time efficiency. 3D-printed resin teeth provide a reproducible model for standardized testing. | Printed teeth do not replicate dentin hardness/radiopacity; anatomical variations absent; clinical applicability requires caution |
| Özdoğru and Keskin (2023) [34] | Turkey | In vitro (resin) | Kiddy, AF Baby, One G + AF Baby, hand K-files | 50 resin block canals | Canal transportation, time | Kiddy best centered; glide path improved AF Baby performance | Glide path improves shaping efficiency | Resin blocks lack tooth resistance and irrigation simulation |
| Shanker and Patil (2023) [35] | India | In vitro (microbiological + radiographic) | Kedo-SH (hand NiTi), Kedo-SG Blue (rotary), Pro AF Baby Gold (rotary) | 51 extracted primary molars divided into 3 groups of 17 teeth | Microbial reduction (E. faecalis CFUs), obturation quality (T-scoring: taper, density, length) | Pro AF Baby Gold showed greatest microbial reduction and highest ideal obturation (length, density, taper). Kedo-SG Blue also effective, better than Kedo-SH. T-scores: group III > II > I. All groups showed statistically significant CFU reduction post-instrumentation. | Rotary files outperform hand files in shaping and cleaning; Pro AF Baby Gold delivers optimal obturation and disinfection | Radiographs were 2D; no CBCT validation; simulated conditions; Metapex was the obturation material in all samples. |
| Faus-Llácer et al. (2022) [36] | Spain | In vitro (Micro-CT) | Endogal Kids vs Reciproc Blue | 60 canals in molars | Dentin removal (3 levels) | Reciproc preserved more coronal dentin | Reciproc less invasive | Only dentin evaluated; no obturation or cleaning |
| Tofangchiha et al. (2022) [37] | Iran | In vitro | Kedo-S, RaCe, hand K-files | 120 root canals of primary second molars | Cleaning efficacy in apical, middle, and coronal thirds using India ink method | Kedo-S showed significantly superior cleaning in the coronal third compared to RaCe and hand files; no significant differences in middle/apical thirds | Kedo-S files enhance cleaning efficiency in coronal areas; advantageous in pediatric pulpectomy | In vitro only; India ink is limited in quantifying biofilm or tissue debris; results may not generalize to clinical settings |
| Mohamed et al. (2022) [38] | Egypt | In vitro (CBCT) | Kedo-S Square | 60 anterior teeth | Canal shaping, preparation accuracy | Good taper and shaping with rotary file | Rotary viable in anterior teeth | Not validated in vivo |
| Subramaniam et al. (2022) [39] | India | In vitro (SEM) | Kedo-S, Pro AF Baby Gold, K-files | 60 anterior extracted teeth | Smear layer removal scores | Rotary removed more smear layer | Superior canal wall cleanliness with rotary | Only smear layer assessed; limited to anterior teeth |
| Peedikayil et al. (2022) [40] | India | In vitro | Kedo-SG Blue, Pro AF Baby Gold, Kedo-SH, ProTaper Hand | 60 extracted single-rooted primary teeth (15 per group) | Amount of apical debris extrusion using Myers and Montgomery model | Kedo-SG Blue extruded the least debris (0.00187 μg) followed by Pro AF Baby Gold (0.00340 μg); hand files (Kedo-SH: 0.00413 μg; ProTaper: 0.00500 μg) | Rotary systems, especially Kedo-SG Blue, significantly reduce apical debris extrusion in primary teeth | Does not simulate in vivo anatomy or irrigation dynamics; results may vary with different canal morphologies and irrigants |
| Mahmoud et al. (2022) [41] | Egypt | In vitro (SEM) | Kedo-SG Blue, Wave One Gold, hand K-files | 75 mandibular primary second molars, 25 per group | Dentinal crack formation in coronal, middle, and apical thirds | Cracks observed in 41.3% (WOG), 24.0% (Kedo-SG Blue), and 13.3% (hand K-file). - Hand files had significantly fewer cracks than rotary systems, especially in coronal and apical thirds. | Kedo-SG Blue produced fewer dentinal cracks than WOG. Manual files caused the least. Rotary systems still show promise but may increase crack risk. | No PDL simulation; SEM offers surface-level insights; clinical loading and cyclic fatigue not accounted for |
| Rosas et al. (2021) [42] | Brazil | In vitro | Manual H-file (Angelus), Sequence Baby Rotary, rotary + PDT | 48 root canals of primary molars, 12 per group | Bacterial count (CFU/mL) of E. faecalis pre- and post-intervention using ANOVA and Dunnett’s test | All intervention groups significantly reduced E. faecalis. PDT group (G3) had the highest bacterial reduction (log reduction: 1.96), followed by rotary (1.58) and manual (1.36) | PDT + rotary instrumentation most effective in disinfection; supports PDT as adjunctive tool | No antimicrobial irrigants used (only saline); ex vivo model; laser PDT lacks clinical standardization for primary teeth |
| Singh et al. (2022) [43] | India | In vitro (CBCT) | NiTi K-files, ProTaper Next (PTN), OneShape (OS), WaveOne (WO) | 60 canals from 44 extracted primary teeth (15 per group) | Canal transportation, CAR, RDT, dentinal cracks, instrumentation time (min) | PTN had least canal transportation; OS best centering ability. NiTi K-files preserved maximum dentin and caused minimum cracks. WO had shortest instrumentation time (1.83 min). | Rotary files such as PTN and OS maintain canal shape better than hand files; WO offers speed advantage; K-files preserve more dentin | CBCT provided objective evaluation; study lacked evaluation of debris removal or obturation quality; only short canals studied |
| Swaminathan et al. (2022) [44] | India | In vitro (CBCT) | Kedo-S vs Mtwo rotary files | 50 extracted mandibular primary first molars (25 per group) | Instrumentation time, dentin removal (mesial/distal), lateral perforation (CBCT) | Kedo-S showed significantly shorter instrumentation time (53.4 s) than Mtwo (192.28 s). No significant difference in dentin removal. Mtwo caused more apical perforations (28%) than Kedo-S (12%). | Kedo-S is safer and faster, with lower perforation risk in primary teeth than traditional rotary systems | Focused only on distal canals; no obturation or cleaning efficacy evaluated; needs validation in curved canals or clinical setting |
| Haridoss et al. (2022) [45] | India | In vitro (CBCT) | Kedo-S (pediatric rotary), Mtwo (NiTi) | 50 extracted primary mandibular first molars (25 per group) | Canal transportation and centering ability (at 2, 4, 6 mm from CEJ) | Both file systems showed minimal and comparable transportation and maintained centering ability. Kedo-S showed slightly more distal transport. Mtwo showed better centering at apical level, but not significant statistically. | Kedo-S and Mtwo are both safe for primary root canal shaping with minimal iatrogenic risk | In vitro CBCT-based data only; lacks long-term follow-up; clinical correlation needed with real pulp tissue or curved canals |
| Islam et al. (2021) [46] | Cyprus | In vitro (CBCT) | ProTaper Gold, RaceEvo, R-Motion | 60 curved primary molars | Canal transportation, dentin removal | ProTaper removed more dentin; RaceEvo preserved anatomy | Newer rotary systems better for canal preservation | Not clinically validated |
| Güçyetmez Topal et al. (2021) [47] | Turkey | In vitro (CBCT) | EndoArt Ni-Ti Gold Pedo Kit vs hand K-files | 30 extracted primary molars (15/group) with 7mm root length | Canal transportation (BL and MD), instrumentation time, dentin removal (coronal, middle, apical thirds) | No significant difference in canal transportation or instrumentation time. EndoArt removed significantly more dentin at coronal and middle thirds (p<0.05). Both systems kept transportation < 0.15 mm (clinically acceptable). | EndoArt rotary system provides more conical canal shaping and efficient dentin removal in coronal/middle thirds | Small sample; no microbial/debris evaluation; no long-term obturation or clinical performance tracked |
| Rathi et al. (2021) [48] | India | In vitro | Kedo-S, Pro AF Baby Gold | 20 extracted molars | Cleaning, apical extrusion | Pro AF had better cleaning, less debris extrusion | Consider Pro AF over Kedo-S | No clinical correlation or follow-up |
| Pawar et al. (2021) [49] | India | Ex vivo Study | Hand K-files, Kedo-S, XP-endo Shaper | 45 extracted primary canines (n=15/group) | Apical debris extrusion, instrumentation time | XP-endo Shaper extruded least debris (0.84 mg), followed by Kedo-S (1.20 mg) and hand K-files (2.13 mg). XP-endo also had the shortest instrumentation time (2.38 min). | Motorized files reduce debris extrusion and save time; especially useful in pediatric endodontics | Only anterior straight-rooted teeth used; findings not generalizable to molars or resorbed teeth |
| Waly et al. (2021) [50] | Egypt/Saudi Arabia | Ex vivo (CBCT) | Kedo-S, Pro AF Baby Gold, hand K-files | 72 canals from extracted 2° molars | Transportation, dentin thickness, centering ratio | Rotary systems faster; shaping comparable | Efficient with no compromise in canal shape | CBCT-based; lacks biological data |
| Alfadhli et al. (2021) [51] | Saudi Arabia, Egypt | In vitro | K-files (manual), Kedo-SG (rotary) | 58 canals from primary molars (31 rotary, 27 manual) | Cleaning efficacy (India ink), instrumentation time | Kedo-SG group had significantly shorter preparation time (58 s vs 91 s) and higher complete canal cleaning (Score 0: 12 vs 2) | Rotary files improve cleaning efficacy and reduce time in pulpectomy | Resin clearing method; limited to ex vivo conditions; India ink is not equivalent to real pulp tissue |
| Kalita et al. (2021) [52] | India | In vitro | Kedo-S, ProTaper, hand K-files | 120 root canals | Cleaning efficacy, time | Kedo-S best in coronal/middle thirds; fastest file | Improves cleaning and saves time | Apical cleaning not significantly better |
| Eldemery et al. (2021) [53] | Egypt | In vitro (CBCT) | Manual SS K-files vs AF™ Baby Rotary | 40 roots from mandibular primary molars (20/group) | RDT at coronal, middle, apical thirds using CBCT | Rotary AF™ Baby File removed significantly less dentin than manual files at all levels; Manual group had almost double % of dentin loss (35–37% vs 17%) at all thirds. | Rotary files better preserve radicular dentin structure and are more suitable for curved primary roots | Only dentin thickness measured; no evaluation of canal centering, cleaning efficacy, or post-operative behavior |
| Preethy et al. (2019) [54] | India | In vitro | Hand K-files, K3, Kedo-S | 36 primary canines | Apical debris extrusion | Kedo-S had significantly less debris extrusion | Reduces risk of extrusion-associated pain | Only anterior teeth assessed |
| Katge et al. (2019) [55] | India | In vitro | Prime Pedo, DXL-Pro, H-files | 60 root canals in primary molars | Cleaning efficacy using India ink | Prime Pedo and DXL-Pro > H-files (coronal, apical thirds) | Pediatric rotary files enhance cleanliness | No difference in middle third; ink lacks clinical correlation |
| Akkam et al. (2019) [56] | Saudi Arabia | In vitro (CBCT) | K-files, Rotary NiTi, Kedo-S | 30 extracted molars | Canal enlargement, obturation | Rotary systems > manual for shaping and fill | Enhanced rotary shaping outcomes | Poster; peer-review status unclear |
| Shaikh and Goswami (2018) [57] | India | In vitro (CBCT) | Revo-S, Sonic MM1500, hand K-files | 75 molars | Centering, canal shaping | Sonic better at apical shaping; rotary better centering | Use combined approach | Time and clinical outcomes not measured |
| Radhika et al. (2017) [58] | India | In vitro (CBCT) | Hand NiTi vs rotary (unspecified) | 40 primary molars | Canal shaping, centering | Rotary showed better centering and shaping | Rotary safer in primary canal prep | File brands not mentioned; outdated scope |
| Katge et al. (2016) [59] | India | In vitro | H-files, Mtwo | 90 canals | Cleaning, instrumentation time | Similar cleaning; Mtwo slower | Manual still relevant in some cases | No obturation or post-operative assessment |
| Selvakumar et al. (2016) [60] | India | In vitro (CT) | Stainless steel K, K3 (0.02/0.04) | 75 molars | Dentin removal, time, perforation risk | K3 (0.02) preserved more dentin | Prefer low taper files in primary molars | Older files; newer pediatric systems not compared |
| Katge et al. (2014) [61] | India | In vitro | K-files, ProTaper, WaveOne | 120 root canals from 84 primary molars | Cleaning efficacy and time | WaveOne best in coronal/middle thirds | Reciprocating better than manual | Older NiTi tech; pediatric-specific files not tested |
| Selvakumar et al. (2014) [62] | India | In vitro (SCT) | K-files, K3 (0.02%, 0.04%) | 75 primary molars | Canal transportation, centering | K3 (0.02%) had best centering and least transportation | Low-taper K3 safe for primary molars | Old tech; no newer pediatric rotary systems used |
| Prabhakar et al. (2014) [63] | India | In vitro experimental | Twisted Files (TF), ProTaper | 30 extracted primary molars (15 per group) | Cutting efficiency (Indian ink removal scored 0–3); statistical comparison via Mann-Whitney U test | Twisted files achieved complete ink removal in 53.3% vs 13.3% with ProTaper (p=0.02); more uniform cleaning with TF; ProTaper removed more dentin unevenly | TF files showed superior cutting efficiency in primary molars and are suitable for pediatric endodontics | Small sample; subjective scoring method (ink); no evaluation of canal transportation or time; adult files used; lack of long-term performance or fracture resistance data |
| Pinheiro et al. (2014) [64] | Brazil | In vitro microbiological study | Manual K-files vs ProTaper rotary (with PDT combinations: TBO/laser, fuchsin/LED, fuchsin/halogen light) | 20 extracted primary molars (E. faecalis infected, 10 per group) | CFU count of E. faecalis before/after instrumentation and PDT (Wilcoxon, t-test, Kruskal-Wallis) | Both manual and rotary instrumentation significantly reduced E. faecalis counts. PDT (all 3 combinations) further enhanced bacterial reduction. No significant difference between rotary and manual groups in baseline or post-PDT counts. | PDT is effective as an adjunct to both manual and rotary instrumentation in reducing E. faecalis in primary teeth | Small sample size (n=10 per group); adult rotary system used; focused only on one bacterial species (E. faecalis); no shaping or obturation outcome assessed; PDT not yet common in clinical pediatric endo |
| Musale and Mujawar (2013) [65] | India | In vitro experimental | ProTaper, ProFile, Hero Shaper (all rotary) vs hand K-files | 60 extracted primary mandibular second molars (15 per group) | Shaping ability (CBCT taper assessment); cleaning efficacy (India ink removal); instrumentation time; instrument distortion | Rotary files produced significantly better canal taper than hand files (p<0.05). Cleaning efficacy: ProTaper > Hero Shaper > ProFile > K-file. K-files had highest mean time (20.7 min) vs rotary (5.6–8.9 min). No distortion in rotary groups; 1 distorted K-file. | Rotary instrumentation yielded faster preparation, cleaner canals, and better taper; beneficial for pediatric clinical use | Adult rotary systems used; operator was a novice with rotary use (bias potential); only one distortion event may not reflect real-world fatigue; CBCT offers high fidelity but limited clinical replication of working conditions |
| Azar et al. (2012) [66] | Iran | In vitro experimental | Mtwo, ProTaper, Manual K-files | 80 extracted mandibular primary molars (160 canals) | Cleaning efficacy via India ink scoring (0–3) in coronal, middle, and apical thirds | No significant difference overall; ProTaper better in coronal/middle thirds, Mtwo more uniform; none cleaned apical third effectively | Adult rotary files showed comparable cleaning to hand files; adaptation of rotary systems in pediatric endo is feasible | Small sample; adult systems tested in primary teeth; subjective scoring system; apical cleaning poor; results may not generalize to newer pediatric systems |
| Pinheiro et al. (2012) [67] | Brazil | In vitro experimental (ex vivo microbiological + SEM) | ProTaper (rotary), K-files (manual), Hybrid (manual + rotary) | 15 primary molars infected with E. faecalis, embedded and instrumented | Instrumentation time; microbial reduction (E. faecalis); SEM analysis of debris and smear layer | Hybrid technique showed highest bacterial reduction (99.58%), but took longest time. Rotary files had shorter time and less smear layer. Manual had more smear layer but less debris. | Rotary NiTi instrumentation is faster and more efficient than manual techniques; hybrid improves disinfection but is time-consuming | Small sample (n=5 per group); no long-term clinical validation; rotary and hybrid both used ProTaper (adult system); unclear if clinical operator variability is reflected |
| Madan et al. (2011) [68] | India | In vitro experimental | ProFiles 0.04 taper (Dentsply) vs manual K-files (Kendo) | 75 extracted primary molar root canals (with 2/3 root intact) | Cleaning efficiency via India ink clearing; Instrumentation time (chronometer) | ProFiles cleaned coronal third better; K-files better in apical third (p<0.001). No significant difference in middle third cleaning. K-files faster in both arches (p<0.001). | Rotary ProFiles offer effective coronal shaping, but K-files excel in apical cleaning. Manual files also saved time. | India ink method lacks microbial relevance; instrumentation time may reflect operator bias; adult rotary system tested in primary roots without taper adaptation for narrow canals |
| Azar and Mokhtare (2011) [69] | Iran | In vitro Experimental (Ex vivo) | Mtwo rotary system vs manual K-files | 70 primary and 70 permanent molars; 120 canals ink-stained and analyzed | Cleaning ability (India ink score in 3 canal thirds); instrumentation time; file fracture incidence | No significant difference in cleaning ability in any third (p > 0.05); rotary files significantly faster (primary: 259s vs 434.7s; permanent: 414.6s vs 831.6s); minimal file fracture | Mtwo files are safe and effective for primary molars; faster than hand files and comparable in cleaning | Adult files (Mtwo) used in pediatric canals; India ink method may not correlate with microbial debridement; no evaluation of canal transportation; no clinical correlation provided |
| Nazari Moghaddam et al. (2009) [70] | Spain | In vitro | ProFile vs hand K-files | 60 single-rooted primary teeth | Time, shaping | Rotary faster, more tapered shape | Better canal preparation | Outdated tech (ProFile); no clinical validation |
| Crespo et al. (2008) [71] | Spain | In vitro | ProFile vs hand K-files | 60 single-rooted primary teeth | Time, shaping | Rotary faster, more tapered shape | Better canal preparation | Outdated tech (ProFile); no clinical validation |
| Kummer et al. (2008) [72] | Brazil | Ex vivo in vitro study | Hero 642 (NiTi rotary) vs hand K-files | 80 extracted human primary teeth (40 per group), embedded in endodontic cubes | Dentin removal (mm² via digital image analysis); instrumentation time (min); canal shape; root perforation incidence | Manual files removed more dentin at all levels (p < 0.05). Rotary files significantly faster (all tooth groups, p < 0.05). More root perforations in areas of advanced resorption (especially mid-root and lingual roots). Rotary resulted in more regular shaping. | Rotary instrumentation is faster and conserves dentin better than manual techniques. Care needed near resorbed areas due to risk of perforation | Complex methodology using embedded cube models, which while accurate, is not replicable in clinical settings. Hero 642 is an adult system. Variable canal anatomy and extent of resorption not fully standardized or accounted for. |
| Nagaratna et al. (2006) [73] | India | In vitro experimental | ProFile 0.04 taper (Dentsply), Stainless Steel K-files | 20 primary mandibular second molars (group I) and 20 permanent molars (Group II) | Preparation time; instrument failure (deformation or fracture); canal shaping: flow, taper, and wall smoothness via elastomeric impressions | Rotary files significantly reduced instrumentation time (primary: 8.51 min vs 13.39 min; permanent: 9.91 min vs 15.99 min, p<0.001). Better canal shaping (flow, taper, and smoothness) in rotary group for most canals. K-files showed more deformation; rotary files had more fracture events. | NiTi rotary (ProFile) showed superior performance in shaping and speed for both primary and permanent molars, though file fractures were noted | Adult rotary files tested in primary teeth; small sample size (n=10 per subgroup); artificial model may not replicate clinical variability; use of elastomeric impression for internal canal morphology is uncommon in current literature |
Pediatric-specific rotary systems such as Kedo-S, Kedo-SG Blue, Pro AF Baby Gold, Prime Pedo, and PedoFlex consistently outperformed manual files in time efficiency, shaping accuracy, and bacterial load reduction was studied by Kalita et al. [52], Amin and Wassel [17], Okasha et al. [16], and Gucyetmez Topal et al. [33]. Advanced evaluations using CBCT and nano-CT confirmed superior canal volume changes and centering with rotary files [23,24,33]. Smear layer removal was significantly better in SEM-based comparisons [39,41].
Rotary instrumentation also minimized apical debris extrusion ([13,40. Files such as Kedo-S Plus, VDW.ROTATE™, EndoArt Pedo Smart Gold, and Graphene-coated prototypes showed advancements in fatigue resistance and cutting efficiency [22,23,31,33]. The 62 in vitro studies demonstrate that pediatric rotary files consistently achieve better canal shaping, shorter instrumentation time, and reduced procedural risks compared to manual systems.
FEA-Based Studies
Only two studies employed FEA modeling to simulate stress and fatigue performance in pediatric rotary files. Monika Sri et al. found that Pro AF Baby exhibited the lowest stress levels and highest fatigue resistance across simulated canal curvatures (30°, 60°, 90°) [74]. Manivannan et al. reported that Kedo-SG showed highest flexibility, while Pro AF Baby withstood bending stress without yield [75] (Table 3).
Table 3
Summary of FEA studies on pediatric rotary file systems
This table presents two FEA-based studies evaluating stress distribution, fatigue resistance, and flexibility of pediatric rotary instruments in simulated primary molar canals. It includes study characteristics, 3D model details, mechanical outcomes, and implications for pediatric endodontics.
3D, three-dimensional; CAD, computer-aided design; FEA, finite element analysis; MPa, megapascal
Von Mises stress: a calculated stress used to predict yielding of materials under complex loading.
| Author (Year) | Country | Study Design | File Systems Evaluated | Sample/Model | Outcome Measures Assessed | Key Findings | Conclusion / Clinical Implication | Remarks |
| Monika Sri et al. (2025) [74] | India | FEA | Kedo-SG Blue-D1, Neoendo Pedo Flex, Pro AF Baby B2 | 3D models of primary molar canals with 30°, 60°, 90° curvature | Maximum stress (MPa), number of fatigue cycles to failure | Pro AF Baby showed lowest stress values and highest fatigue resistance across all canal curvatures. Stress increased with curvature: Kedo-SG showed highest stress at 90° (4063 MPa) and Pro AF the least (2022 MPa). Pro AF completed more cycles before fatigue failure. | Pro AF Baby rotary file is best suited for complex curvatures in primary molars due to superior fatigue resistance and lower stress concentrations | FEA simulations only; no clinical validation; anatomical variations and in vivo loading forces not fully replicated |
| Manivannan et al. (2024) [75] | India | In vitro (FEA) | Pro AF Baby, Kedo-SG, Neoendo Pedoflex | CAD-based FEA simulation using pediatric rotary files | Von Mises stress (bending/torsion), yield limit, flexibility | Kedo-SG showed highest flexibility; Pro AF Baby withstood bending without yielding | Pro AF Baby is ideal for narrow canals; Kedo-SG for curved canals | FEA lacks in vivo validation; depends on mesh and boundary condition accuracy |
Despite the limited number, these FEA-based studies support the mechanical superiority of pediatric rotary systems under stress. However, findings must be interpreted cautiously due to the limitations of simulation fidelity.
Clinical Studies (RCTs and In Vivo Trials)
A total of 26 clinical studies (RCTs and in vivo trials) examined rotary instrumentation outcomes in children [76-101]. Studies originated mainly from India, Egypt, Iran, and other regions (Table 4).
Table 4
Summary of RCTs and clinical studies evaluating pediatric rotary endodontic file systems
This table presents RCTs and prospective clinical studies comparing pediatric rotary and manual file systems in primary teeth. The studies assess clinical outcomes such as instrumentation time, obturation quality, postoperative pain, microbial reduction, and behavior outcomes across diverse clinical settings and populations.
CBCT, cone-beam computed tomography; CFU, colony-forming units; DOM, dental operating microscope; NiTi, nickel-titanium; PSP, phosphor storage plate; RCT, randomized controlled trial; VCAS, Venham Clinical Anxiety Scale; WL, working length
| Author (Year) | Country | Study Design | File Systems Evaluated | Sample/Model | Outcome Measures Assessed | Key Findings | Conclusion/Clinical Implication | Remarks |
| Al-Wesabi et al. (2025) [76] | Yemen | Clinical trial | Kedo-SG Blue, Kedo-S Square, H-files | 72 children | Behavior, pain, instrumentation time | Rotary files improved behavior and reduced pain | Kedo-S Square recommended for efficiency | Short-term behavior only; no follow-up |
| Bohidar et al. (2024) [77] | India | RCT | Manual K-files, Kedo-S | 36 primary molars | Pain over 72 hrs | Rotary group had significantly lower pain | Improves post-operative experience in kids | Subjective pain; no radiographic or microbial success |
| Jeepalyam et al. (2024) [78] | India | RCT | Kedo-SG Blue, Prime Pedo | 50 primary molars | Instrumentation/obturation time, obturation quality | Kedo-SG Blue was faster and better in obturation | More efficient for pediatric pulpectomy | Single-center; no microbial or long-term outcome |
| Thakur et al. (2024) [79] | India | In vivo (RCT) | Prime Pedo™ rotary, DXL-Pro™ rotary, Manual H-files | 51 primary mandibular molars in children aged 4–10 (17 per group) | Instrumentation time, quality of obturation (Coll and Sadrian criteria) | Rotary groups (Prime Pedo™: 65.05 ± 4.02 s, DXL-Pro™: 66.29 ± 4.45 s) had significantly shorter instrumentation times than manual (140.05 ± 5.54s). No significant difference in obturation quality between groups. | Pediatric rotary systems are efficient and reduce chair-side time; obturation quality remains comparable to manual files | Single-blinded study; short follow-up; 2D radiographic evaluation; lacks microbial or pain-related outcome tracking |
| Saxena et al. (2023) [80] | India | RCT | K-files vs Pro AF Baby Gold | 60 primary molars | Post-operative pain, time, obturation | Rotary faster; no difference in pain or obturation | Rotary files help reduce chair time | Pain scoring subjective; no long-term evaluation |
| Kumar and Jeevanandan (2023) [81] | India | RCT | Hand K-files, Kedo-S Square, Kedo-S Plus | 45 children (4–8 yrs); 15/group; single visit pulpectomy | Instrumentation time, obturation quality (Coll and Sadrian), post-operative pain (Wong-Baker), follow-up at 3, 6, 12 months | Kedo-S Plus had shortest time (57.5s), best obturation (100%), and lowest post-operative pain scores | Kedo-S Plus is superior for pediatric molars in clinical efficiency and comfort | Small sample; used PSP radiographs, which may not detect micro voids; lacks microbial or CBCT analysis |
| Kumar and Jeevanandan (2023) [82] | India | Prospective clinical study | Kedo-S Plus pediatric rotary file | 100 primary molars (335 root canals) in 4- to 9-year-old children | Fracture incidence of rotary files (visualized under 8x magnification), canal location | Only 1 file fractured (1%) in 335 canals, specifically in the apical third of the mesiobuccal canal of a maxillary second molar in group D (used 12 times); no fractures in other groups | Kedo-S Plus rotary file has low fracture incidence even when reused multiple times; most fractures occur in curved, narrow canals | Single file design; findings limited to clinical visualization; no fatigue analysis or fracture propagation microscopy included |
| Arora Sowmya et al. (2023) [83] | India | RCT | Rotary vs Manual | 40 mandibular molars | Clinical success, time | Rotary faster, both clinically effective | Rotary is efficient in practice | No behavioral scoring or obturation quality reported |
| Arora et al. (2023([84] | India | In vivo (RCT) | Hand K-files vs Pro AF Baby Gold | 150 primary mandibular molars in 140 children (age 4–7) | Instrumentation time, obturation quality (Coll and Sadrian), post-operative pain at multiple intervals | Rotary instrumentation (Pro AF Baby Gold) required significantly less time (27.44 min vs 50.88 min), higher optimal obturation (76% vs 52%), less pain at 6 and 12 hrs | Rotary technique offers superior efficiency, less post-operative pain, better obturation in pulpectomy | Follow-up limited to 3 weeks; behavior and microbial clearance not evaluated; examiners used PSP not CBCT |
| Abdel Rahman et al. (2023) [85] | Egypt | RCT | Manual H-files, Kedo-SG Blue, Kedo-S Square | 93 primary molars | Time, anxiety (VCAS scale) | Kedo-S Square had lowest anxiety and fastest time | Enhances cooperation in children | Only short-term outcome; no clinical performance tested |
| Patel et al. (2023) [86] | India | RCT | Hand K-files, HeroShaper, Kedo-S Square | 60 mandibular molars | Time, obturation, pain perception | Kedo-S Square fastest; all had similar obturation and pain | Efficient option for short chair-time | Pain data subjective; no follow-up |
| Kumar and Rehman (2023) [87] | India | RCT: in vivo clinical study | Neo Endo Flex rotary files (group II), standard manual files (group I) | 208 deciduous molars in children aged 3–8 years, split into two groups (98 and 90 treated teeth, respectively) | Clinical and radiographic success at 6 and 12 months | No significant difference between microscope and conventional groups in clinical (96.6% vs 97.7%) and radiographic (95.5% vs 98.8%) success at 12 months. DOM (microscope) group showed slightly better outcomes with fewer radiolucencies and resorption cases. | Dental operating microscope can enhance visualization and possibly outcomes in pediatric endo, but results are comparable with conventional treatment when protocols are standardized. | Microscope use adds cost and requires training; patient anxiety due to microscope setup not studied; long-term follow-up beyond 1 year not available |
| Thakur et al. (2023) [88] | India, Indonesia, UAE | RCT: in vivo clinical study | XP-endo Shaper (adaptive), Kedo-SG Blue (rotary), manual K-files | 75 children aged 4–9 years (25 per group); mandibular primary molars | Post-operative pain at 6, 12, 24, 48, 72 hours (Wong-Baker scale) | - XP-endo group showed least post-operative pain at 6 and 12 hrs - Kedo-SG moderate pain - Manual files had highest pain at early time points - By 24 hrs, all groups showed minimal or no pain | XP-endo Shaper adaptive files significantly reduce early post-operative pain in primary molars; optimal for pediatric endo | Sample size limited; only short-term post-operative pain assessed; quality of obturation assessed only via 2D radiograph; no microbial analysis |
| Hadwa et al. (2023) [89] | Egypt | RCT (Triple-blinded) | Kedo-S-Square, Fanta AF™ Baby | Manual K-file | 60 children, 3 groups (n=20 each) | - Instrumentation time (Kedo: 74.75s; Fanta: 76.6s; Manual: 106.2s) - CBCT-based obturation quality (Optimal fill: Kedo 85%, Fanta 75%, K-file 70%) - Post-operative pain scores at 6h, 12h, 24h, 48h lower in rotary groups (significant) | Rotary files (Kedo-S-Square and Fanta AF™ Baby) showed superior instrumentation efficiency, obturation quality, and less postoperative pain compared to manual K-files. Use of CBCT offered reliable 3D assessment. | While the study supports superior performance of rotary systems in terms of pain and efficiency, the small sample size and limited methodological detail (e.g., CBCT calibration, file reuse protocol) warrant cautious interpretation. |
| Babu et al. (2022) [90] | India | Randomized Clinical Trial (RCT) | Pedo-Flex, Kedo-S, Manual NiTi K-files | 75 primary molars in children aged 4–7 years, 25 per group | Instrumentation time, obturation time, quality of obturation, postoperative pain | Rotary files (Pedo-Flex and Kedo-S) had significantly less instrumentation and obturation time and better obturation quality than manual files. Both rotary groups had less postoperative pain. | Pediatric rotary files offer superior efficiency, quality, and reduced post-operative pain vs manual files; no difference between Pedo-Flex and Kedo-S | Short-term follow-up; used 2D radiographs instead of CBCT; no microbial or long-term evaluation conducted |
| Kaushik et al. (2022) [91] | India | RCT | H-files, Flexicon X7, Hyflex CM | 60 primary molars | Instrumentation time, obturation quality | Flexicon X7 had shortest instrumentation time | Rotary systems reduce treatment time | Used Metapex; long-term success not assessed |
| Lakshmanan et al. (2022) [92] | India | RCT | Manual K/H, Kedo-S Square | 45 molars | Aerobic/anaerobic bacteria reduction | Kedo-S Square had 93–95% reduction | Improves microbial efficacy | No long-term clinical/radiographic outcome |
| Pawar et al. (2021) [93] | India/UAE/Israel | RCT | XP-endo Shaper, Kedo-S, Manual K-files | 75 primary molars | Instrumentation time, obturation quality | XP-endo had best obturation and fastest time | Adaptive rotary systems show promise | Cost and complexity may limit routine use |
| Jeevanandan et al. (2021) [94] | India | RCT | K-files, Kedo-SH, Kedo-SG Blue | 45 children | Pain, obturation (Wong-Baker scale) | SG Blue best fill (80%) and least day-1 pain | SG Blue preferred for comfort + clinical result | Pain subjective; CBCT not used for obturation |
| Shah et al. (2021) [95] | India | In vivo RCT | Hand K-files, Kedo-S, Pro-AF Baby GOLD | 45 primary mandibular molars in 42 children aged 5–9 | Instrumentation time, obturation time, radiographic quality (voids, extent) | Kedo-S: least instrumentation time (19.25 min). Pro-AF: least obturation time (4.62 min), highest optimal fill (58.5%), and lowest voids. K-files showed inferior outcomes | Pediatric rotary systems (Kedo-S, Pro-AF) significantly reduce chair-side time and improve obturation quality vs manual instrumentation | Radiographic evaluation only (2D); single operator; short-term outcomes only evaluated |
| Lakshmanan and Jeevanandan (2020) [96] | India | RCT | Kedo-S Square rotary file, H-file, K-file | 45 primary mandibular molars (15 per group) in children aged 4–7 years | Instrumentation time (seconds), quality of obturation (Coll and Sadrian criteria) | Kedo-S Square had shortest instrumentation time (73.46 s) and highest optimal obturation rate (67%). Manual files took more time (H: 126.86 s; K: 105.6 s) and had lower obturation quality (H: 20%, K: 33%). | Kedo-S Square rotary system is superior in terms of reduced time and optimal obturation compared to traditional manual files | Short-term follow-up only; no microbial analysis; 2D radiographs limit evaluation; no long-term success data included |
| Ghadge et al. (2020) [97] | India | RCT | Prime Pedo, ProTaper Universal, H-files | 45 primary mandibular molars | Quality of obturation, voids | Prime Pedo showed highest optimal fill and fewer voids | Pediatric rotary improves obturation outcomes | Small sample; voids radiographically assessed only |
| Govindaraju et al. (2017) [98] | India | RCT | K-files, ProTaper, Mtwo | 45 primary mandibular molars | Time, obturation | Rotary groups faster with equal obturation | Favor rotary for time-saving | Bacterial clearance not measured |
| Mokhtari et al. (2017) [99] | Iran | RCT | Mtwo with apex locator vs hand | 80 children | Working length accuracy, time | Rotary faster; similar WL accuracy | Efficient with apex locator | No obturation or cleaning results |
| Subramaniam et al. (2013) [100] | India | RCT | HERO Shaper (rotary NiTi) vs hand NiTi vs SS K-files | 60 primary molars (children aged 5–9, 3 groups of 20) | Aerobic and anaerobic microbial CFU counts pre- and post-instrumentation | All 3 systems significantly reduced CFU (p<0.001); no significant difference in microbial reduction among groups | Rotary NiTi files were as effective as hand NiTi and SS files in reducing bacterial load in primary molar root canals | No long-term clinical outcomes measured; only one canal per tooth sampled (palatal/distal); lack of blinding in clinical procedures; irrigation was only saline, no antimicrobial agents used |
| Ochoa-Romero et al. (2011) [101] | Mexico | RCT | K3 rotary NiTi (SybronEndo) vs stainless steel hand K-files | 40 primary molars (20 per group), pulpectomy in necrotic teeth | Instrumentation time, obturation time, and obturation quality (optimal, underfilled, overfilled) | Rotary significantly reduced instrumentation time (63%) and obturation time (68%). Optimal filling in 80% of rotary cases vs 50% in manual group. Statistically significant improvement (p < 0.05). | Rotary instrumentation in pulpectomy significantly improves efficiency and obturation quality in pediatric patients | Small sample size (n=20/group), single-operator bias, short follow-up duration, adult file (K3) used, not pediatric-specific system |
Instrumentation Time and Efficiency
A major advantage of rotary files, consistently reported across clinical trials, was a significant reduction in instrumentation time compared to manual techniques. The data show that rotary systems reduced procedural time by approximately 26% to 78% across different studies. Saxena et al. reported that instrumentation with Pro AF Baby Gold (8.33 minutes) was 60% faster than with manual K-files (20.83 minutes) [78]. Similarly, Patel et al. found that Kedo-S Square required only 57.47 seconds, a 77.5% time reduction, compared to the 255.99 seconds needed for manual files. This enhanced efficiency contributes to shorter appointment times and may improve patient cooperation [84].
Pain and Patient Behavior
Rotary systems were associated with lower postoperative pain [77,88] and better child behavior outcomes [76,85].
Obturation Quality
Obturation outcomes assessed using radiographs or the Coll and Sadrian criteria showed higher rates of optimal fills in rotary file groups [82,84,89].
Fracture and Safety
Only one file fracture was reported in a large clinical sample using Kedo-S Plus [82], highlighting excellent durability.
Microbial Reduction and Radiographic Success
Only a few studies reported bacterial reductions [92,100], while radiographic follow-ups confirmed high success rates above 95% [87,99]. Clinical evidence across 26 studies confirms that pediatric rotary files are superior in time efficiency, comfort, and obturation quality, with favorable behavior outcomes and low complication rates.
Review Articles
A total of 19 review articles were included: 6 systematic reviews, 1 umbrella review, 1 meta-analysis, and 11 narrative reviews [6,102-119]. These reviews analyzed shaping ability, procedural time, safety, and canal adaptation (Table 5).
Table 5
Summary of review articles evaluating pediatric rotary endodontic systems
This table compiles systematic reviews, meta-analyses, umbrella reviews, and narrative reviews that assess the design evolution, efficacy, clinical performance, and adoption of pediatric-specific rotary endodontic file systems in primary teeth. It highlights key comparisons between manual and rotary instrumentation, addresses evidence gaps, and reflects expert consensus on file selection and usage in pediatric endodontics.
CBCT, cone-beam computed tomography; GPs, general practitioners; GRADE, Grading of Recommendations, Assessment, Development and Evaluations; KAP, knowledge, attitude, practices; MA, meta-analysis; NiTi, nickel-titanium; RCT, randomized controlled trial; RoB, risk of bias; SAF, self-adjusting file; SEM, scanning electron microscopy; SR, systematic review
| Author (Year) | Country | Study Design | File Systems Evaluated | Sample/Model | Outcome Measures Assessed | Key Findings | Conclusion/Clinical Implication | Remarks |
| Patnana et al. (2025) [102] | India | Umbrella review | Hand vs rotary files | 6 SRs/MAs included | Time, obturation, RoB | Rotary faster (3.2 min), but evidence low certainty | Advocates for more RCTs on pediatric rotary | GRADE scores low; RoB concerns |
| Sulaiman et al. (2025) [103] | India | Systematic review | ProTaper, WaveOne Gold, Reciproc, Kedo-S, SAF, OneShape, XP-Endo Shaper | 5 in vitro studies on extracted primary teeth | Dentinal microcrack formation (via micro-CT, SEM, stereomicroscope) | Rotary systems with greater taper (ProTaper, XP-Endo, Reciproc) produced more cracks; SAF and Kedo-S systems showed fewer cracks; cracks most frequently occurred 3 mm from apex; hand files caused fewer cracks but are slower | Pediatric-specific rotary systems such as Kedo-S, SAF preserve dentin better than aggressive adult files | Only in vitro studies included; lacks meta-analysis; variable methodologies across studies; unclear generalizability to clinical settings |
| Gala et al. (2024) [6] | India | Systematic review and meta-analysis | Rotary (Kedo-S, Kedo-SG, ProTaper, XP-Endo, LightSpeed) vs hand Files (K-files, H-files) | 9 RCTs (495 children, primary teeth) | Instrumentation time, quality of obturation | Rotary systems showed significantly reduced instrumentation time compared to manual files (pooled effect: 10.37 minutes; 95% CI: 8.23–12.51; p < 0.001). Pediatric-specific files such as Kedo-S also reduced postoperative pain. | Rotary files, especially pediatric-specific systems, offer superior clinical efficiency and better obturation quality in pulpectomies | Heterogeneous methodologies, limited databases searched, most studies from India, no long-term outcome meta-analysis |
| Tiwari et al. (2024) [104] | India | Cross-sectional + review | Pediatric rotary files (general discussion); no direct brand tested | 108 dentists (54 pediatric, 54 general); literature synthesis | KAP; awareness of pediatric tools | High awareness of pediatric-specific tools but low actual use among general dentists. 87% of pedodontists and 83% of GPs acknowledged increased perforation risk with adult rotary files. Pediatric tools were preferred for improved safety, comfort, and visibility. | Kid-sized dentistry improves clinical efficiency, safety, and patient comfort; should be promoted through education and professional advocacy. | Based on survey and narrative; lacks direct clinical or in vitro evidence for rotary instrumentation performance; geographically limited to Jabalpur zone. |
| Parmar and Agrawal (2024) [105] | India | Narrative review | Kedo-series, Prime Pedo, Denco | Literature | Evolution, usage trends | Pediatric files improve quality and reduce time | Technological progress supports rotary adoption | Not systematic; lacks data quality assessment |
| Gumro et al. (2023) [106] | India | Narrative review | Kedo-S, Kedo-SG, Kedo-SG Blue, Kedo-S Square, Pro-AF Baby Gold, Prime Pedo, DXL-Pro™, Sani Kid, Fanta | Literature overview | Evolution, design features, advantages and disadvantages | Pediatric rotary files offer improved cleaning, controlled taper, reduced chair time, better adaptation in curved/narrow canals; each file system has unique metallurgy and flexibility properties | Pediatric rotary instrumentation is superior to manual; clinician must choose based on anatomy and case | Descriptive only; lacks comparative or quantitative evaluation; relies on secondary references |
| Kaushik et al. (2023) [107] | India | Narrative review | Kedo-S, Denco, AF Baby, etc. | Literature overview | Evolution, specs, outcomes | Pediatric files are more flexible and child-friendly | Trend favors rotary-specific pediatric files | No systematic grading; descriptive only |
| Haridoss et al. (2022) [108] | India | Systematic review | Reciprocating vs rotary vs hand files | 12 in vitro studies | Time, canal transportation | No significant time or shaping difference between rotary types | Rotary/reciprocating better than hand | Only lab studies; no clinical RCTs included |
| Kaushal et al. (2022) [109] | India | Systematic review | SAF, ProTaper Next, others | 7 in vitro studies | Debris extrusion | Rotary less extrusive; SAF best | Rotary safer for apical region | Only lab studies; no in vivo validation |
| Ranjana et al. (2021) [110] | India | Narrative review | Kedo, Pro AF Baby Gold, Pedoflex (Neoendo) | Literature synthesis | Innovations in pediatric rotary systems | Pediatric rotary systems improve cleaning, are child-specific in taper/design, and reduce procedural time | Rotary systems like Kedo and Pro AF Baby Gold are efficient and safe in primary teeth | Descriptive overview only; lacks comparative data or methodology; includes general innovations |
| Casaña Ruiz et al. (2022) [111] | Spain | Systematic review | ProTaper, WaveOne Gold, XP-Endo Shaper, Reciproc, Kedo-S, SAF, OneShape, BioRace, TRUShape, etc. | 11 studies (RCTs, in vitro, ex vivo studies) on primary teeth instrumentation | Instrument design (length, taper, diameter), instrumentation time, dentin removal, debris extrusion, obturation quality | Rotary files such as Kedo-S and XP-Endo performed better in preserving anatomy, reducing debris extrusion, and maintaining seal; Reciproc and ProTaper removed more dentin and caused more microcracks. SAF resulted in least dentin removal but more wall damage. | Pediatric-specific files (Kedo-S, XP-Endo) recommended for safety and effectiveness in primary pulpectomies | Limited number of high-quality pediatric-specific studies; heterogeneous methods across included studies; no meta-analysis performed |
| Devi et al. (2021) [112] | India | Narrative review | General rotary systems | Narrative review | Morphological benefits, handling advantages | Rotary systems reduce fatigue and improve canal preservation | Supports transition to rotary endo | No statistical evaluation or grading |
| Padmawar et al. (2021) [113] | India | Narrative review | Kedo-S, Prime Pedo, Sani Kid, Denco | Literature overview | Evolution and clinical relevance | Pediatric files improve efficiency and acceptance | Shift toward rotary is justified | Lacks systematic methodology |
| Parimala et al. (2021) [114] | India | Narrative review | ProTaper, FlexMaster, HERO 642, Mtwo, K3, Kedo-S, Kedo-SG, Kedo-SG Blue, Pro AF Baby, Prime Pedo, DXL-Pro, etc. | Literature review | Design, advantages, disadvantages, clinical use | Rotary instrumentation reduces working time, improves canal shaping, and enhances obturation quality. Pediatric-specific files such as Kedo-S and Pro AF Baby are better adapted to primary canal anatomy. Clinical outcomes improve with pediatric-specific files. Post-operative pain, success rates, and reduced iatrogenic errors have been reported in cited studies. | Pediatric-specific rotary systems should be preferred over adult systems in primary teeth; proper training essential | Lacks statistical synthesis or risk of bias assessment; relies heavily on secondary citations; no direct data comparison included |
| Pitchiah and Shivashankarappa (2020) [115] | India | Narrative review | Adult systems (ProTaper, Hero 642, FlexMaster, WaveOne, Reciproc, Mtwo, K3, ProTaper Next) Pediatric-specific (Kedo-S, Kedo-SG, SG Blue, Square, Pro AF Baby, Prime Pedo, DXL-Pro) | Literature review | Evolution and classification of rotary systems | Kedo-S files overcome anatomical and practical limitations of adult rotary systems in primary teeth. Each generation improves on taper, flexibility, and cyclic fatigue resistance. Pediatric rotary systems reduce time, increase obturation quality. | Pediatric-specific rotary files are tailored to primary canal anatomy and offer improved clinical outcomes | Descriptive review only; lacks comparative statistical analysis; based on past literature and expert commentary |
| Manchanda et al. (2020) [116] | Hong Kong | Systematic review + MA | Multiple rotary and manual systems | 13 RCTs | Time, obturation, post-operative pain | Rotary systems reduced pain and time | Supports rotary use in children | Moderate certainty; only English studies |
| Jindal et al. (2020) [117] | India | Narrative review | ProTaper, K3, FlexMaster, HERO 642, Mtwo, WaveOne, Kedo-S | Literature review | File design features, shaping technique, clinical pros/cons | Rotary instruments reduce chair time and improve child cooperation. Each system has unique taper, tip, cutting design. Kedo-S is first pediatric-specific rotary file. FlexMaster, Mtwo, HERO have various taper/pitch profiles. | Rotary systems enhance efficiency and reduce errors in pediatric pulpectomy | Review lacks quantitative comparison; based largely on expert opinion; no systematic review or grading applied |
| Alotaibi et al. (2020) [118] | Saudi Arabia | Narrative review | NiTi Rotary Files (Kedo-S, D1, E1), Hand files | Literature overview | Root canal anatomy, instrumentation techniques, obturation materials | NiTi rotary systems offer high flexibility, reduced working time, and better adaptation in curved primary canals. Techniques vary significantly between primary and permanent teeth. MTA, iodoform-based pastes, and calcium hydroxide are commonly used. | Rotary files improve shaping and cleaning efficiency in primary root canals; material choice must align with resorption timeline | Narrative only; lacks experimental validation or quantitative data; based heavily on secondary references and case diagrams |
| Ahmed (2013) [119] | Malaysia | Narrative review | ProFile, ProTaper, Hero 642, FlexMaster, K3, Mtwo, Ultrasonic, Manual K-files | Compilation of clinical and in vitro studies (2000–2012) | Root morphology, EAL accuracy, instrumentation time, cleaning efficacy, irrigant interactions | Rotary NiTi reduces instrumentation time but may risk over-instrumentation. Apex locators effective even in resorbed roots. Irrigant interactions (NaOCl + CHX) can form harmful precipitates. | Advocates rotary NiTi with caution in primary molars. Highlights need for irrigant safety protocols and careful working length determination | Review synthesizes multiple studies, but lacks quantitative meta-analysis. Not all file systems evaluated in pediatric-specific protocols. Generalizations may not reflect individual clinical variability. |
Meta-analyses reported significantly shorter instrumentation times and better obturation with rotary files [6]. Umbrella and systematic reviews endorsed pediatric-specific systems such as Kedo-S, SAF, and XP-Endo, though some noted moderate to low certainty of evidence [102,103,111]. Narrative reviews emphasized evolution in file design and highlighted better acceptance of rotary instrumentation by both practitioners and children [105,115]. The review literature supports the clinical utility and efficiency of pediatric-specific rotary files, though methodological inconsistencies across included studies necessitate further high-quality research.
Case Reports and Miscellaneous Evidence
Only two case-based publications were eligible. The reports by Suresh et al. and Barr et al. described clinical success using pediatric rotary files such as Kedo-S Plus, Kedo Nano, and ProFile in primary teeth [120,121]. Although case reports are low on the evidence hierarchy, they offer real-world insights into operator file preferences and individualized canal shaping strategies (Table 6).
Table 6
Summary of case reports and technical notes on rotary endodontic instrumentation in primary teeth
This table highlights case-based evidence and technical descriptions of rotary file systems used in pediatric endodontics. It summarizes procedural outcomes, instrumentation techniques, and shaping efficacy reported in real-world clinical settings. Although limited in generalizability, these studies demonstrate the practical use of various pediatric and adapted adult rotary files.
BMP, biomechanical preparation; NiTi, nickel-titanium
| Author (Year) | Country | Study Design | File Systems Evaluated | Sample/Model | Outcome Measures Assessed | Key Findings | Conclusion/Clinical Implication | Remarks |
| Suresh et al. (2024) [120] | India | Case report | Kedo-S Plus, Kedo Square, Kedo Nano Plus | 3 primary molars | Single-visit BMP, obturation | All three files achieved optimal shaping and BMP | All generations useful depending on clinical need | Case report; not generalizable |
| Barr et al. (2000) [121] | USA | Technical note + case series | ProFile® NiTi rotary (.04 taper) | Case-based use in primary incisors and molars (radiographic examples only) | Descriptive: canal debridement efficiency, ease of obturation, radiographic fill | NT rotary files produced funnel-shaped preps; improved debridement and easier filling; faster and more predictable outcomes in primary teeth | Rotary instrumentation can be safely adapted for pulpectomy in primary teeth; improves fill quality and clinical efficiency | No experimental data; based on operator experience; early use of adult files in primary teeth; lacks comparative or outcome-based metrics; technique sensitive and equipment dependent |
Discussion
This scoping review included 111 studies spanning over two decades (2000-2025), systematically mapping the evolution, design rationale, and clinical performance of rotary instrumentation in pediatric dentistry. The review confirms that pediatric-specific rotary systems, such as Kedo-S, Pro AF Baby Gold, Kedo-SG Blue, and Prime Pedo, have become central to clinical practice due to their efficiency, safety, and adaptation to primary tooth morphology [12-56]. The inclusion of studies from 2000-2008 adds valuable historical context, particularly highlighting early rotary file applications such as ProFile, K3, FlexMaster, and HERO 642 in primary molars [63-70]. Although these earlier systems were originally designed for permanent teeth, multiple in vitro studies demonstrated their feasibility in pediatric canals [71-73]. The comparative evaluations showed significant reductions in instrumentation time ranging from approximately 26% to 78% compared to manual hand files across the analyzed studies and acceptable shaping ability. However, these earlier systems had limitations, including a higher risk of over-preparation and less flexibility. This highlighted the clinical demand that led to the development of dedicated pediatric-specific systems, such as Kedo-S, beginning in 2016.
Evidence Synthesis: Strengths and Caveats
The evidence consistently demonstrated that rotary instrumentation, particularly systems designed for pediatric use, provided shorter instrumentation times, better shaping ability, and fewer procedural errors compared to manual files. This was reinforced by 62 in vitro studies, which showed improved canal centering (CBCT/nano-CT), less dentin removal, reduced apical debris extrusion, and more uniform obturation [12-73]. Clinical trials (n = 26) showed that rotary systems also decreased postoperative pain, enhanced child cooperation, and led to higher obturation success rates [76-101]. However, questions remain about overgeneralization of in vitro results to clinical scenarios. Many in vitro studies used resin blocks or single-rooted anterior teeth, which may not reflect the complexities of curved molar canals [16,31,33,34,51]. Moreover, a substantial number of studies relied on subjective scoring systems without microbial or longitudinal correlation. Interestingly, these earlier studies had limited evaluation of obturation quality and no assessment of microbial clearance or file fracture behavior areas that newer studies have addressed.
Alignment with Objectives
This review fulfilled its key aims by comprehensively cataloguing pediatric rotary file systems, synthesizing design features such as taper, metallurgy, and motion mechanics, and mapping clinical, biomechanical, and microbial outcomes across various study designs. However, while the review provides a thorough classification of rotary systems, some subcategories, such as reciprocating pediatric files and multi-file versus single-file systems, were underexplored due to insufficient data in the included studies.
Limitations
Several limitations were identified in this review. Over 70% of studies were from India, raising concerns about global generalizability. Differences in caries prevalence, tooth morphology, and practice models may influence outcomes elsewhere. Variable study quality was another issue, as few studies employed blinding, detailed randomization protocols, or long-term radiographic follow-up. Many in vitro models also failed to simulate clinical conditions, limiting translatability. Additionally, outcomes such as microbial reduction or fracture resistance were inconsistently reported, restricting comparisons across systems. A primary limitation, inherent to the scoping review methodology, is the absence of a formal risk of bias or GRADE assessment. While this is consistent with PRISMA-ScR guidelines, it means the certainty of evidence for specific outcomes was not formally rated. Furthermore, the included studies exhibited significant heterogeneity in their methodologies. This included varied outcome measures (e.g., different scoring criteria for obturation quality), inconsistent follow-up periods in clinical trials, and diverse in vitro models (such as extracted teeth versus resin blocks), which limits the direct comparability of findings and precluded any meta-analysis.
Strengths
This review is the first comprehensive scoping review to include 111 studies over a 25-year period and is PRISMA-ScR compliant. It integrates data across a wide evidence hierarchy from FEA simulations and imaging to clinical trials and systematic reviews. The addition of earlier studies enriched the temporal evolution and technological trajectory of pediatric file systems. Moreover, our review uniquely mapped rotary system generations, offering a visual framework to support clinical decision-making and academic discourse.
Implications for Practice and Research
The cumulative evidence justifies the clinical transition from manual to pediatric-specific rotary instrumentation. These systems offer faster, more predictable outcomes with lower procedural risk, especially in young, anxious patients. Nonetheless, from a critical standpoint, durability and cost-effectiveness of systems such as Pro AF Baby or Kedo-SG Blue remain poorly studied, and most studies excluded teeth with advanced resorption, complex canal systems, or clinical failures, which could skew success rates.
To improve evidence certainty, future research must focus on head-to-head trials comparing next-gen systems (Kedo-S Plus vs Endogal Kids vs Prime Pedo), adopt standardized outcome metrics (volumetric shaping, microbial clearance, CBCT obturation scoring), ensure longitudinal follow-up (≥12 months), include multi-ethnic populations for generalizability, and evaluate emerging adjuncts such as photodynamic therapy, AI-based working length estimation, and 3D printing for training.
Conclusions
Rotary instrumentation has transformed pediatric endodontics, offering child-friendly systems that reduce treatment time, improve shaping outcomes, and elevate clinical predictability. This scoping review of 111 studies confirms the efficacy and safety of pediatric-specific rotary files, yet highlights the ongoing need for high-quality, globally representative trials. Clinicians are encouraged to adopt these innovations while remaining critical of study heterogeneity and mindful of individual patient anatomy. This review synthesizes over two decades of evidence, highlighting the transition from modified adult rotary files to purpose-built pediatric systems and reaffirming the clinical and biomechanical superiority of child-specific designs.
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Abstract
Rotary instrumentation is increasingly popular in pediatric endodontics, but the evidence for pediatric-specific systems remains fragmented. This scoping review aimed to map the design features, clinical outcomes, and evidence gaps of rotary file systems used in primary teeth. We conducted a systematic search of PubMed, Scopus, Web of Science, and Google Scholar for studies published between 2000 and 2025. We included in vitro, clinical, and imaging-based studies, reviews, and case reports. Data on file design, study characteristics, and outcomes were extracted and synthesized. From 424 records, 111 studies were included. The results showed that pediatric-specific rotary systems (e.g., Kedo-S, Pro AF Baby Gold, Kedo-SG Blue) were consistently associated with reduced instrumentation time and improved canal shaping compared to manual techniques. Pediatric-specific rotary files demonstrate clear procedural advantages over manual methods. However, significant heterogeneity in study quality and limited global representation necessitate cautious interpretation. Future research should prioritize multicenter randomized controlled trials with long-term follow-up to provide higher-quality evidence.
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Details
1 Pediatric and Preventive Dentistry, Sri Ramachandra Institute of Higher Education and Research, Chennai, IND
2 Pedodontics and Preventive Dentistry, Primary Health Care Corporation, Doha, QAT
3 Pediatric and Preventive Dentistry, Al-Baha University, Al-Baha, SAU
4 Pediatric and Preventive Dentistry, Sri Ramachandra Dental College and Hospital, Chennai, IND