Functionalized Graphene Oxide Shields Tooth Dentin from Decalcification

Abstract

This in vitro study assessed the efficacy of functionalized graphene oxide (f-GO) nanocomposites on the decalcification of dentin, because dental caries of the root surface is becoming one of the new problems in aged society. Hydroxyapatite plates (HAP) and dentin slices were coated with f-GO nanocomposites by comparing them to silver diamine fluoride as a positive control, then treated with decalcification solutions such as ethylenediaminetetraacetic acid and citrate at 37°C for 24 h. Scanning electron microscopy (SEM) revealed significant protection of the surface morphology of HAP and dentin. On the other hand, a cariogenic Streptococcus mutans growth was inhibited by f-GO nanocomposites. In addition, cytotoxicity of them to epithelial cells was much less than that of povidone-iodine, which is commonly used for oral disinfectant. We synthesized 5 different f-GO nanocomposites such as GO–silver (Ag), GO-Ag–calcium fluoride (CaF2), GO-CaF2, GO-zinc, and GO–tricalcium phosphate (Ca3(PO4)2). They were standardized by evaluating under SEM, transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetry analysis (TGA), and Raman spectra after being synthesized in an aseptic technique. The abilities of GO-Ag, GO-Ag-CaF2, and GO-CaF2 nanocomposites were most preventive for decalcification. In addition, GO-Ag and GO-Ag-CaF2 almost completely inhibited S. mutans growth. However, they did not exhibit cytotoxicity to epithelial cells except at the highest concentration (0.1 w/v%) of GO-Ag and GO-Ag-CaF2. Furthermore, these f-GO nanocomposites exhibited less or no discoloration of dentin, although commonly used silver diamine fluoride causes discoloration of dentin to black. Thus, these f-GO nanocomposites are useful to protect dental caries on the tooth root that becomes a social problem in aged society.

Synergistic effect of graphene oxide/calcium phosphate nanofiller in a dentin adhesive on its dentin bond integrity and degree of conversion. A scanning electron microscopy, energy dispersive X‐ray spectroscopy, Fourier transform infrared, micro‐Raman, and bond strength study

“…It has been reported in the literature that C containing materials (such as GO) possess superior chemical, mechanical, and electronic properties, when compared with other identical materials (Tiwari, Thakur, Adhikari, Zhu, & Wang, 2020). GO containing nanocomposites that are enriched in sp 3 ‐bonded C, could have anti‐demineralization effect on the dentin, and they can seal off dentinal tubules forming a protective layer with their characteristic antibacterial effects (M. Z I. Nizami, Nishina, Yamamoto, Shinoda‐Ito, & Takashiba, 2020).…”

Electrophoresis-Aided Biomimetic Mineralization System Using Graphene Oxide for Regeneration of Hydroxyapatite on Dentin

“…Our finding was in line with the study by Nizami et al, in which the remineralization was observed for the group with the addition of GO. However, 8 h of mineralization time was needed in our study compared to 24 h of mineralization time in the study by Nizami et al [ 41 ].…”

Graphene functionalized with nanosilver particle‐modified methacrylate‐based bonding agent improves antimicrobial capacity and mechanical strength at tooth orthodontic bracket interface

“…Functionalization of GNP with silver was carried out using previously described protocols. [ 24 ] Silver nitrate and graphene nanoplatelets solutions were obtained by dissolving 80 mg of AgNO3 (Sigma Aldrich, USA) and 50 mg of GNP in 20 ml of distilled water, followed by 30 min of sonication, respectively. The prepared mixtures were added dropwise with to a 1 W/W% NaOH solution (Sigma Aldrich, USA), which was vigorously stirred until pH reached alkaline (pH = 8).…”