Comparative evaluation of volumetric changes between two pediatric rotary files (Kedo-S plus, Kedo-SG blue) and manual files (hand K-files) during canal preparation of primary mandibular molars: an in-vitro nano-CT analysis

Pediatric endodontics has become popular due to advancements in cleaning, shaping and irrigation systems, resulting in faster and effective removal of infected pulp, saving time, and creating a pathogen-free environment. The patented rotary file system, Kedo-S, designed for primary teeth, introduced a single file generation for efficient pulp therapy. However, there are currently no studies assessing canal preparation in primary mandibular molars using nano-CT (computed Tomography). To evaluate the volumetric changes of two recently introduced pediatric rotary file systems in comparison with conventional hand file systems in primary mandibular molar using an ultra-high resolution nano-CT. This in-vitro study was performed in extracted primary mandibular molar based on certain inclusion and exclusion criteria. Samples were prepared and working length was determined before the pre-operative scan using a high resolution nano-CT device (SkyScan 2214, Bruker, Kontich, Belgium). A single well-experienced pediatric dentist prepared the canals using three file systems: Kedo-S plus, Kedo-SG blue and Hand K-files. A post-operative scan was performed similar to pre-operative scan. Image reconstruction was performed with NRecon software for 3D volumetric visualization and analysis of the root canals. Kedo-SG blue file systems had the highest mean difference in the canal volume (8.85%). Hand K-files had the least difference at (1.24%) of canal volume. Kedo-S plus file system had a mean canal volume difference (6.14%) which is closer to hand K-files. Rotary file systems resulted in a significant enlargement of canals compared to hand files.

Volumetric change; Pediatric endodontics; Mandibular molars; Nano-CT; Kedo-S plus; Kedo-SG blue; K-files

[1] Xiao J, Alkhers N, Kopycka-Kedzierawski D, Billings R, Wu T, Castillo D, et al. Prenatal oral health care and early childhood caries prevention: a systematic review and meta-analysis. Caries Research. 2019; 53: 411–421.

[2] Nishant N, Goyal A, Morankar R, Gauba K, Jaiswal M. Awareness among pediatricians regarding oral health care in children including those with special health care needs: a cross-sectional survey. Journal of Family Medicine and Primary Care. 2020; 9: 4151.

[3] Naidu RS, Pahel B, Niederman R, Nunn JH. Promoting oral health in early childhood: the role of the family, community and health system in developing strategies for prevention and management of ECC. Frontiers in Public Health. 2021; 9: 716695.

[4] Smaïl-Faugeron V, Glenny A-M, Courson F, Durieux P, Muller-Bolla M, Fron Chabouis H. Pulp treatment for extensive decay in primary teeth. Cochrane Database of Systematic Reviews. 2018; 5: CD003220.

[5] Spodzieja K, Olczak-Kowalczyk D. Premature loss of deciduous teeth as a symptom of systemic disease: a narrative literature review. International Journal of Environmental Research and Public Health. 2022; 19: 3386.

[6] Reddy ER, Raju SS, Sandipamu T, Kiranmayi M, Mudusu SP, Saraswati SD. Modified conventional root canal shaping technique in primary teeth: an in vivo study. International Journal of Clinical Pediatric Dentistry. 2022; 15: S8–S11.

[7] Alves RAA, Souza JB, Gonçalves Alencar AH, Pécora JD, Estrela C. Detection of procedural errors with stainless steel and NiTi instruments by undergraduate students using conventional radiograph and cone beam computed tomography. Iranian Endodontic Journal. 2013; 8: 160–165.

[8] Zupanc J, Vahdat‐Pajouh N, Schäfer E. New thermomechanically treated NiTi alloys—a review. International Endodontic Journal. 2018; 51: 1088–1103.

[9] Liang Y, Yue L. Evolution and development: engine-driven endodontic rotary nickel-titanium instruments. International Journal of Oral Science. 2022; 14: 12.

[10] Katge F, Dixit UB. Root and root canal anatomy of primary mandibular central incisor, lateral incisor, and canine in indian children: a cone beam computed tomography study. International Journal of Dentistry. 2022; 2022: 7191134.

[11] Ahmed HMA, Musale PK, El Shahawy OI, Dummer PMH. Application of a new system for classifying tooth, root and canal morphology in the primary dentition. International Endodontic Journal. 2020; 53: 27–35.

[12] Jeevanandan G. Kedo-S paediatric rotary files for root canal preparation in primary teeth—case report. Journal of Clinical and Diagnostic Research. 2017; 11: ZR03–ZR05.

[13] Karatas OH, Toy E. Three-dimensional imaging techniques: a literature review. European Journal of Dentistry. 2014; 08: 132–140.

[14] Mao T, Neelakantan P. Three-dimensional imaging modalities in endodontics. Imaging Science in Dentistry. 2014; 44: 177.

[15] Acar B, Kamburoğlu K, Tatar İ, Arıkan V, Çelik HH, Yüksel S, et al. Comparison of micro-computerized tomography and cone-beam computerized tomography in the detection of accessory canals in primary molars. Imaging Science in Dentistry. 2015; 45: 205.

[16] Azevedo MAD, Silva TG da, Fernandes Â, Piasecki L, Fariniuk LF, Silva Neto UX da. Endodontic retreatment using a single instrument from four nickel-titanium systems—a micro-CT study. Brazilian Dental Journal. 2020; 31: 605–610.

[17] Erpaçal B, Adıgüzel Ö, Cangül S. The use of micro-computed tomography in dental applications. International Dental Research. 2019; 9: 78–91.

[18] Navas J, Doranala S, Khushnud A, Sinha J, Jadhav A, Gudapati S, et al. Evaluation of the root canal morphology of human teeth by cone beam computed tomography and micro-computed tomographic—a systematic review with meta-analysis. Journal of Pharmacy and Bioallied Sciences. 2022; 14: 254.

[19] Ahmed HMA. Nano-computed tomography: current and future perspectives. Restorative Dentistry & Endodontics. 2016; 41: 236.

[20] Jeevanandan G, Thomas E. Volumetric analysis of hand, reciprocating and rotary instrumentation techniques in primary molars using spiral computed tomography: an in vitro comparative study. European Journal of Dentistry. 2018; 12: 21–26.

[21] Sandhu SV, Tiwari R, Bhullar RK, Bansal H, Bhandari R, Kakkar T, et al. Sterilization of extracted human teeth: a comparative analysis. Journal of Oral Biology and Craniofacial Research. 2012; 2: 170–175.

[22] Selvakumar H, Kavitha S, Thomas E, Anadhan V, Vijayakumar R. Computed tomographic evaluation of K3 rotary and stainless steel K file instrumentation in primary teeth. Journal of Clinical and Diagnostic Research. 2016; 10: ZC05–8.

[23] Barasuol JC, Alcalde MP, Bortoluzzi EA, Duarte MAH, Cardoso M, Bolan M. Shaping ability of hand, rotary and reciprocating files in primary teeth: a micro-CT study in vitro. European Archives of Paediatric Dentistry. 2021; 22: 195–201.

[24] Vora MS, Nihal NK, Ramachandra JA. Root canal irrigants in primary teeth. World Journal of Dentistry. 2015; 6: 229–234.

[25] Azar M, Nikaein A, Safi L. Comparison of the cleaning capacity of Mtwo and ProTaper rotary systems and manual instruments in primary teeth. Dental Research Journal. 2012; 9: 146.

[26] Prabhakar AR, Yavagal C, Naik SV, Dixit K. Reciprocating vs rotary instrumentation in pediatric endodontics: cone beam computed tomographic analysis of deciduous root canals using two single-file systems. International Journal of Clinical Pediatric Dentistry. 2016; 9: 45–49.

[27] Nazari Moghaddam K, Mehran M, Farajian Zadeh H. Root canal cleaning efficacy of rotary and hand files instrumentation in primary molars. Iranian Endodontic Journal. 2009; 4: 53–57.

[28] Mehlawat R, Kapoor R, Gandhi K, Kumar D, Malhotra R, Ahuja S. Comparative evaluation of instrumentation timing and cleaning efficacy in extracted primary molars using manual and NiTi rotary technique—invitro study. Journal of Oral Biology and Craniofacial Research. 2019; 9: 151–155.

[29] Ramazani N, Mohammadi A, Amirabadi F, Ramazani M, Ehsani F. In vitro investigation of the cleaning efficacy, shaping ability, preparation time and file deformation of continuous rotary, reciprocating rotary and manual instrumentations in primary molars. Journal of Dental Research, Dental Clinics, Dental Prospects. 2016; 10: 49–56.

[30] Namdev R, Rajain T, Tsomu K. Evaluation and Comparison of effectiveness of Kedo-S pediatric rotary files vs manual instrumentation for root canal treatment in primary molars. International Journal of Clinical Pediatric Dentistry. 2023; 16: 22–29.

[31] Swaminathan K, Rakkesh KM, Haridoss S. Computed tomographic assessment of remaining dentin and risk of perforation after kedo-s and mtwo rotary instrumentation in root canals of primary teeth: an in vitro study. International Journal of Clinical Pediatric Dentistry. 2022; 15: S87–S91.

[32] Hülsmann M, Peters OA, Dummer PMH. Mechanical preparation of root canals: shaping goals, techniques and means. Endodontic Topics. 2005; 10: 30–76.

[33] Metzger Z, Zary R, Cohen R, Teperovich E, Paqué F. The quality of root canal preparation and root canal obturation in canals treated with rotary versus self-adjusting files: a three-dimensional micro-computed tomographic study. Journal of Endodontics. 2010; 36: 1569–1573.

[34] Zhao D, Shen Y, Peng B, Haapasalo M. Root canal preparation of mandibular molars with 3 Nickel-titanium rotary instruments: a micro-computed tomographic study. Journal of Endodontics. 2014; 40: 1860–1864.

[35] Özlek E, Gündüz H. Effectiveness of different rotary file systems in removing the root canal filling material: a micro-computed tomography study. Journal of Dental Research, Dental Clinics, Dental Prospects. 2021; 15: 273–278.