Nanodiamond–Gutta Percha Composite Biomaterials for Root Canal Therapy

Abstract

Root canal therapy (RCT) represents a standard of treatment that addresses infected pulp tissue in teeth and protects against future infection. RCT involves removing dental pulp comprising blood vessels and nerve tissue, decontaminating residually infected tissue through biomechanical instrumentation, and root canal obturation using a filler material to replace the space that was previously composed of dental pulp. Gutta percha (GP) is typically used as the filler material, as it is malleable, inert, and biocompatible. While filling the root canal space with GP is the standard of care for endodontic therapies, it has exhibited limitations including leakage, root canal reinfection, and poor mechanical properties. To address these challenges, clinicians have explored the use of alternative root filling materials other than GP. Among the classes of materials that are being explored as novel endodontic therapy platforms, nanodiamonds (NDs) may offer unique advantages due to their favorable properties, particularly for dental applications. These include versatile faceted surface chemistry, biocompatibility, and their role in improving mechanical properties, among others. This study developed a ND-embedded GP (NDGP) that was functionalized with amoxicillin, a broad-spectrum antibiotic commonly used for endodontic infection. Comprehensive materials characterization confirmed improved mechanical properties of NDGP over unmodified GP. In addition, digital radiography and microcomputed tomography imaging demonstrated that obturation of root canals with NDGP could be achieved using clinically relevant techniques. Furthermore, bacterial growth inhibition assays confirmed drug functionality of NDGP functionalized with amoxicillin. This study demonstrates a promising path toward NDGP implementation in future endodontic therapy for improved treatment outcomes.

The antimicrobial activity of nanoparticles: present situation and prospects for the future

“…For example, nanodiamond-functionalized amoxicillin in combination with gutta-percha for root canal treatment can eliminate residual bacteria after root canal filling. 75 In addition, due to the proliferation of bacteria and the reduction in pH in the course of treatment, orthodontic treatment often leads to the formation of dental plaque chalk, and brackets coated with CuO and ZnO NPs can effectively inhibit the growth of S. mutans; however, the coatings also affect the appearance of the brackets. 76 Maxillofacial prostheses placed in a complex external environment containing a variety of flora have been shown to develop biofilms, thereby increasing the incidence of tissue inflammation surrounding the prostheses.…”

Antibacterial Activity and Biocompability of Zinc Oxide and Graphite Particles as Endodontic Materials

“…Gutta-percha is typically used as a fi ller material as it is malleable, inert and biocompatible. However, traditional gutta-percha has certain shortcomings including leakage, root canal reinfection, and poor mechanical properties 7) . Therefore, new fi llers and composites are widely being studied to overcome these issues.…”

“…It is known, that ZnO nanoparticles have selective toxicity to bacteria but exhibit minimal eff ects on human cells 6) . Moreover, it has been reported that the size and surface of carbon-based nanomaterial (nanoparticles, fullerenes, singlewalled carbon nanotubes, graphene oxide) play a signifi cant role in the antibacterial activity [7][8][9][10] . Graphite has been evaluated as a biomedical material in heart valves, biosensors and joints 11) .…”

Dental Applications of Nanodiamonds

“…Recently, gutta-percha (GP) reinforced with anti-bacterial NDs has been evaluated as a possible endodontic material. 44 . Because of their bio-fluorescent…”

“…Incorporation of NDs in GP has made it made possible to deliver power antibiotics to the root canal. In a recent study, Lee et al 44 successfully incorporated NDs bound to amoxicillin (NDamoxicillin) into GP and observed that not only the composite ND-GP exhibited enhanced bactericidal properties against Streptococci via prolonged drug release but increased Young's modulus, tensile strength and yield strength were also observed. 44 This study maybe the first of many which could lead to development of endodontic materials that not only can deliver antibiotics to the canal but also carry regenerative growth factors to enhance root and pulpodentine regeneration.…”