Room-temperature rapid self-assembled biocompatible MOFs as an Instant, temporary tooth sealant

Abstract

Tooth discoloration is a commonly occurring phenomenon, due to adsorption of coloring substances inside the pores of tooth enamel. In this research, we developed a Room-Temperature Rapid Self-assembly method for Biocompatible Metal-Organic Framework(MOF) sealants. We experimented using combinations between two metal acetates(Zn, Mn) and three types of ligands commonly known to be unharmful to humans(L-(+)-Tartaric acid, L-Glutamic acid, L-Aspartic acid), resulting in development of crystalline materials between Zn-Tartaric acid and Mn-Tartaric acid. The products were characterized using X-ray Diffraction(XRD), Infrared Analysis(IR), Differential Scanning Calorimetry(DSC), Thermogravimetric Analysis(TGA), confirming the formation of MOFs. We also conducted a biocompatibility test using neural stem cells for the MOFs and its reactants, concluding that Zn-Tartrate could be safely used at 7.5 mu g/mL concentration, preserving approximately 95 % cell viability. Then, we confirmed the availability of tooth coating of both MOFs using primary human teeth, and experimented the prevention of tooth discoloration by immersing the coated teeth in beverages that contain coloring substances; Cola, Red Wine, Coffee. Finally, we used Scanning Electron Microscope(SEM) and Energy Dispersive X-ray Spectroscopy(EDS) to measure the amount of metal element remaining on the brushed tooth surface, concluding that Zn-Tartrate is the optimal MOF for temporary tooth sealants. Furthermore, we opened a new possibility for rapid synthesis of biocompatible coating, and the mass production of non-toxic MOFs that can be utilized in the biomedical field.