Remineralization of Dentin with Cerium Oxide and Its Potential Use for Root Canal Disinfection

Abstract

Yinlin Wang,1 Xinyue Zhang,2 Haiyan Zheng,1 Zihuai Zhou,1 Si Li,1 Jimin Jiang,1 Mingxing Li,1 Baiping Fu1 1Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Clinical Research Center for Oral Diseases of Zhejiang Province, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, People’s Republic of China; 2School of Health Policy and Management, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, People’s Republic of ChinaCorrespondence: Baiping Fu; Mingxing Li, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Clinical Research Center for Oral Diseases of Zhejiang Province, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, People’s Republic of China, Email [email protected]; [email protected]: This study was to investigate a novel antibacterial biomimetic mineralization strategy for exploring its potential application for root canal disinfection when stabilized cerium oxide was used.Material and Methods: A biomimetic mineralization solution (BMS) consisting of cerium nitrate and dextran was prepared. Single-layer collagen fibrils, collagen membranes, demineralized dentin, and root canal system were treated with the BMS for mineralization. The mineralized samples underwent comprehensive characterization using various techniques, including transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Fourier transform infrared spectroscopy (FTIR), scanning transmission electron microscopy (STEM), selected-area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and micro-CT. Additionally, the antimicrobial properties of the BMS and the remineralized dentin were also analyzed with broth microdilution method, live/dead staining, and SEM.Results: Cerium ions in the BMS underwent a transformation into cerium oxide nanoparticles, which were deposited in the inter- and intra-fibrillar collagen spaces through a meticulous bottom-up process. XPS analysis disclosed the presence of both Ce (III) and Ce (IV) of the generated cerium oxides. A comprehensive examination utilizing SEM and micro-CT identified the presence of cerium oxide nanoparticles deposited within the dentinal tubules and lateral canals of the root canal system. The BMS and remineralized dentin exhibited substantial antibacterial efficacy against E. faecalis, as substantiated by assessments involving the broth dilution method and live/dead staining technique. The SEM findings revealed the cell morphological changes of deceased E. faecalis.Conclusion: This study successfully demonstrated antibacterial biomimetic mineralization as well as sealing dentinal tubules and lateral branches of root canals using cerium nitrate and dextran. This novel biomimetic mineralization could be used as an alternative strategy for root canal disinfection.Keywords: cerium oxide, dextran, biomimetic mineralization, root canal disinfection

Keywords

• cerium oxide
• dextran
• biomimetic mineralization
• root canal disinfection