小児歯科根管治療革命：小児用ロータリーシステムの進化、効率、将来に関する20年間の物語

Preservation of primary teeth plays a vital role in maintaining arch integrity and guiding the eruption of permanent successors. Pulpectomy remains the treatment of choice for retaining non-vital primary teeth; however, traditional manual instrumentation is often time-consuming and technically demanding because of the complex and resorbing root morphology. Over the past decades, the advent of pediatric-specific nickel-titanium (NiTi) rotary systems has revolutionized endodontic practice in children by offering enhanced precision, safety, and efficiency. This narrative review synthesizes the developmental trajectory, design innovations, metallurgical advancements, and clinical performance of rotary file systems specifically designed for primary teeth. The literature, drawn from major databases spanning 2000-2025, highlights the transformation from modified adult files to pediatric-optimized systems, such as Kedo-S (Kedo Dental, Chennai, India), Kedo-SG Blue (Kedo Dental), Pro AF Baby Gold (Dentobizz, Yavatmal, India), and Fanta AF™ (Fanta Dental Materials, Shanghai, China), which integrate shorter lengths, variable tapers, and heat-treated or nano-coated NiTi alloys. These systems have demonstrated superior canal shaping, reduced instrumentation time, improved obturation quality, and greater patient cooperation than conventional hand files. Advancements in metallurgy, including controlled memory, gold and blue heat treatments, and nanocoating, have markedly improved file flexibility, fatigue resistance, and cutting control. However, challenges regarding technique sensitivity, cost, and training requirements persist. This review underscores the importance of adhering to precise torque and speed parameters, ensuring correct working length determination, and maintaining irrigation safety to avoid procedural mishaps. Emerging trends, such as artificial intelligence (AI)-assisted imaging, nanotechnology-driven coatings, reciprocating motion systems, and 3D-printed simulation training, promise to further refine future pediatric rotary endodontics. Collectively, these innovations represent a shift toward safer, faster, and more predictable pulpectomy outcomes. Rotary instrumentation has evolved from the adaptation of adult techniques to a specialized, evidence-based cornerstone of contemporary pediatric dental care.