A nano-CaF2-containing orthodontic cement with antibacterial and remineralization capabilities to combat enamel white spot lesions

Jianru Yi; Quan Dai; Michael D Weir; Mary A S Melo; Christopher D Lynch; Thomas W Oates; Ke Zhang; Zhihe Zhao; Hockin H K Xu

doi:10.1016/j.jdent.2019.07.010

A nano-CaF₂-containing orthodontic cement with antibacterial and remineralization capabilities to combat enamel white spot lesions

J Dent. 2019 Oct:89:103172. doi: 10.1016/j.jdent.2019.07.010. Epub 2019 Jul 18.

Authors

Jianru Yi¹, Quan Dai², Michael D Weir³, Mary A S Melo³, Christopher D Lynch⁴, Thomas W Oates³, Ke Zhang⁵, Zhihe Zhao⁶, Hockin H K Xu⁷

Affiliations

¹ State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Dept. of Orthodontic and Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, China; Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21021, USA.
² Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21021, USA; Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Department of General Dentistry, College of Stomatology, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China.
³ Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21021, USA.
⁴ Restorative Dentistry, University Dental School and Hospital, University College Cork, Wilton, Cork, Ireland.
⁵ Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21021, USA; School of Stomatology, Capital Medical University, Beijing, China. Electronic address: tuzizhangke@163.com.
⁶ State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Dept. of Orthodontic and Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, China. Electronic address: zhzhao@scu.edu.cn.
⁷ Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21021, 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. Electronic address: hxu@umaryland.edu.

PMID: 31326528
DOI: 10.1016/j.jdent.2019.07.010

Abstract

Objectives: The objectives of this study were to develop a resin-modified glass ionomer containing nanoparticles of calcium fluoride (nCaF₂) and dimethylaminohexadecyl methacrylate (DMAHDM) for the first time and investigate the antibacterial and remineralization properties.

Methods: nCaF₂ was synthesized using a spray-drying method and characterized using a transmission electron microscope. Twenty weight percentage (wt%) nCaF₂ and 3 wt% DMAHDM were incorporated into a RMGI (GC Ortho LC). Enamel shear bond strength (SBS) and cytotoxicity were determined. Fluoride (F) and calcium (Ca) ion releases were assessed. Biofilm live/dead staining, metabolic activity, polysaccharide and lactic production, and colony-forming units (CFU) were evaluated. The remineralization ability was determined by measuring the effects of cements on enamel surface hardness and lesion depth.

Results: Incorporating 20 wt% nCaF₂ and 3 wt% DMAHDM did not compromise the SBS (p > 0.1). The decrease of pH from 7.0 to 4.0 significantly increased the F and Ca ion releases. The new cement greatly reduced the metabolic activity, polysaccharide and lactic acid productions, and lowered the biofilm CFU by 3 log, compared to commercial control (p < 0.05). The new cement increased the enamel hardness by 56% and decreased the lesion depth by 43%, compared to control (p < 0.05). The cell viability at 7 days against the new cement extracts was 82.2% of that of the negative control in culture medium without any extracts.

Conclusions: The novel orthodontic cement containing nCaF₂ and DMAHDM achieved much stronger antibacterial and remineralization capabilities and greater enamel hardness than the commercial control did, without compromising the orthodontic bracket-enamel SBS and biocompatibility.

Clinical significance: The novel bioactive and nanostructured orthodontic cement is promising to inhibit enamel demineralization, white spot lesions and caries in orthodontic treatments.

Keywords: Antibiofilm; Enamel hardness; Nano CaF(2); Orthodontic cement; Remineralization; White spot lesions.

Published by Elsevier Ltd.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anti-Bacterial Agents / pharmacology
Anti-Bacterial Agents / therapeutic use*
Dental Caries / drug therapy*
Dental Caries / prevention & control
Dental Cements / chemistry*
Dental Cements / pharmacology
Dental Enamel*
Glass Ionomer Cements / chemistry*
Humans
Nanoparticles / chemistry*
Orthodontic Brackets
Tooth Remineralization*

Substances

Anti-Bacterial Agents
Dental Cements
Glass Ionomer Cements