Yansong Ma1, Ning Zhang2, Michael D Weir3, Yuxing Bai4, Hockin H K Xu5. 1. Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing, 100050, China. 2. Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing, 100050, China; Biomaterials & Tissue Engineering Division, Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, Baltimore, MD 21201, USA. 3. Biomaterials & Tissue Engineering Division, Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, Baltimore, MD 21201, USA. 4. Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing, 100050, China. Electronic address: byuxing@263.net. 5. Biomaterials & Tissue Engineering Division, Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, Baltimore, MD 21201, USA; Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Mechanical Engineering, University of Maryland, Baltimore County, MD 21250, USA. Electronic address: hxu@umaryland.edu.
Abstract
OBJECTIVES: White spot lesions due to biofilm acid-induced enamel demineralization are prevalent in orthodontic treatments. The aim of this study was to develop a novel bioactive multifunctional cement with protein-repellent, antibacterial and remineralizing capabilities, and investigate the effects on enamel hardness and lesion depth in vitro for the first time. MATERIALS AND METHODS: 2-Methacryloyloxyethyl phosphorylcholine (MPC), dimethylaminohexadecyl methacrylate (DMAHDM), and nanoparticles of amorphous calcium phosphate (NACP) were incorporated into a resin-modified glass ionomer (RMGI). Extracted human premolars had brackets bonded via four groups: (1) Transbond XT (TB), (2) RMGI (GC Ortho LC), (3) RMGI+MPC+DMAHDM, (4) RMGI+MPC+DMAHDM+NACP. Demineralization was induced via a dental plaque microcosm biofilm model. Samples were tested using polarized light microscopy (PLM) for lesion depth. Enamel hardness was tested for different groups. RESULTS: Incorporating MPC, DMAHDM and NACP did not affect enamel bond strength. "RMGI+MPC+DMAHDM+NACP" group had the least lesion depth in enamel (p<0.05). Groups with NACP had the highest enamel hardness (p<0.05). Mineral loss (ΔS) in enamel for NACP group was about one third that for RMGI control. "RMGI+MPC+DMAHDM" had greater effect on demineralization-inhibition, compared to RMGI and TB controls. "RMGI+MPC+DMAHDM+NACP" was more effective in protecting enamel prisms from dissolution by biofilm acids, compared to RMGI and TB control groups. CONCLUSION: The Novel "RMGI+MPC+DMAHDM+NACP" cement substantially reduced enamel demineralization adjacent to orthodontic brackets, yielding much less lesion depth and greater enamel hardness under biofilm acid attacks than commercial controls. The clinical significance is that the novel multi-agent (RMGI+MPC+DMAHDM+NACP) method is promising for a wide range of preventive and restorative applications to combat caries.
OBJECTIVES: White spot lesions due to biofilm acid-induced enamel demineralization are prevalent in orthodontic treatments. The aim of this study was to develop a novel bioactive multifunctional cement with protein-repellent, antibacterial and remineralizing capabilities, and investigate the effects on enamel hardness and lesion depth in vitro for the first time. MATERIALS AND METHODS:2-Methacryloyloxyethyl phosphorylcholine (MPC), dimethylaminohexadecyl methacrylate (DMAHDM), and nanoparticles of amorphous calcium phosphate (NACP) were incorporated into a resin-modified glass ionomer (RMGI). Extracted human premolars had brackets bonded via four groups: (1) Transbond XT (TB), (2) RMGI (GC Ortho LC), (3) RMGI+MPC+DMAHDM, (4) RMGI+MPC+DMAHDM+NACP. Demineralization was induced via a dental plaque microcosm biofilm model. Samples were tested using polarized light microscopy (PLM) for lesion depth. Enamel hardness was tested for different groups. RESULTS: Incorporating MPC, DMAHDM and NACP did not affect enamel bond strength. "RMGI+MPC+DMAHDM+NACP" group had the least lesion depth in enamel (p<0.05). Groups with NACP had the highest enamel hardness (p<0.05). Mineral loss (ΔS) in enamel for NACP group was about one third that for RMGI control. "RMGI+MPC+DMAHDM" had greater effect on demineralization-inhibition, compared to RMGI and TB controls. "RMGI+MPC+DMAHDM+NACP" was more effective in protecting enamel prisms from dissolution by biofilm acids, compared to RMGI and TB control groups. CONCLUSION: The Novel "RMGI+MPC+DMAHDM+NACP" cement substantially reduced enamel demineralization adjacent to orthodontic brackets, yielding much less lesion depth and greater enamel hardness under biofilm acid attacks than commercial controls. The clinical significance is that the novel multi-agent (RMGI+MPC+DMAHDM+NACP) method is promising for a wide range of preventive and restorative applications to combat caries.
Authors: Hong Chen; Yunhao Tang; Michael D Weir; Lei Lei; Radi Masri; Christopher D Lynch; Thomas W Oates; Ke Zhang; Tao Hu; Hockin H K Xu Journal: RSC Adv Date: 2019-12-17 Impact factor: 4.036
Authors: Wen Zhou; Xinyu Peng; Xuedong Zhou; Andrea Bonavente; Michael D Weir; Mary Anne S Melo; Satoshi Imazato; Thomas W Oates; Lei Cheng; Hockin H K Xu Journal: Int J Mol Sci Date: 2020-09-02 Impact factor: 5.923
Authors: Elena Ferrando-Magraner; Carlos Bellot-Arcís; Vanessa Paredes-Gallardo; José Manuel Almerich-Silla; Verónica García-Sanz; Mercedes Fernández-Alonso; José María Montiel-Company Journal: Medicina (Kaunas) Date: 2020-01-29 Impact factor: 2.430