Nanoparticle coatings of Ni-Ti alloy and possibilities in Endodontics: A narrative review

Abstract

Background: Nickel-titanium (Ni-Ti) endodontic files are revolutionizing root canal therapy because of their remarkable flexibility, shape memory, and corrosion resistance. Nonetheless, cyclic fatigue, corrosion-related fractures, and biofilm development have restricted their clinical efficacy. Recent developments in nanotechnology provide solutions using surface coatings with nanoparticles to enhance the mechanical, chemical, and biological properties of Ni-Ti alloys. Materials and Methods: Current developments in nanoparticle coatings for Ni-Ti alloy are investigated in this narrative study. Of the 57 papers generated from a preliminary literature assessment, only 10 fit the inclusion criteria for relevance, approach, and scientific interest. Results: The selected studies highlight a spectrum of nanoparticles: Titanium dioxide (TiO₂), Zirconia (ZrO₂), Silver (Ag), Silicon carbide (SiC), Graphene oxide (GO), Hydroxyapatite (HA), Carbon nanotubes (CNTs), and Fullerene-like tungsten disulfide (IF-WS₂). Fatigue resistance, wear resistance, corrosion resistance, and antibacterial properties of Ni-Ti alloy coated with these nanoparticles have shown significant development. These coatings not only extend the lifetime of Ni-Ti alloy but also reduce bacterial colonization, therefore improving the possible rates of root canal treatment success. Physical vapor deposition, sol-gel dip coating, electrodeposition, chemical deposition technique and direct current magnetron reactive sputtering have been evaluated among several coating techniques. These coatings have therapeutic value depending on homogeneity, adhesive strength, and biocompatibility. Excellent coating performance is thought to depend critically on the eradication of the natural titanium oxide layer from Ni-Ti alloys. Conclusion: Despite these positive advancements, numerous challenges still exist, including regulatory approval, coating durability, and the need for long-term clinical validation. Self-healing coatings, bioactive layers for regenerative endodontics, and intelligent coatings with antimicrobial release driven by environmental changes should be the main focus of further studies. Bringing these discoveries into practical application depends on cooperation among materials scientists, nanotechnologists, and endodontists, thereby improving the performance and durability of Ni-Ti endodontic files.