Novel low-shrinkage-stress nanocomposite with remineralization and antibacterial abilities to protect marginal enamel under biofilm

Ghalia Bhadila; Xiaohong Wang; Wen Zhou; Deepak Menon; Mary Ann S Melo; Silvia Montaner; Thomas W Oates; Michael D Weir; Jirun Sun; Hockin H K Xu

doi:10.1016/j.jdent.2020.103406

Novel low-shrinkage-stress nanocomposite with remineralization and antibacterial abilities to protect marginal enamel under biofilm

J Dent. 2020 Aug:99:103406. doi: 10.1016/j.jdent.2020.103406. Epub 2020 Jun 8.

Authors

Ghalia Bhadila¹, Xiaohong Wang², Wen Zhou³, Deepak Menon⁴, Mary Ann S Melo⁵, Silvia Montaner⁴, Thomas W Oates⁶, Michael D Weir⁷, Jirun Sun⁸, Hockin H K Xu⁹

Affiliations

¹ Ph.D. Program in Dental Biomedical Sciences, Biomaterials and Tissue Engineering Division, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Department of Pediatric Dentistry, Faculty of Dentistry, King AbdulAziz University, Jeddah 21589, Saudi Arabia.
² Volpe Research Center, American Dental Association Foundation, Frederick, MD 21704, USA.
³ Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; State Key Laboratory of Oral Diseases, Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, National Clinical Research Centre for Oral Diseases, Sichuan University, Chengdu, 610041, China.
⁴ Department of Oncology and Diagnostic Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA.
⁵ Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, MD 21201, USA.
⁶ Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA.
⁷ Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA. Electronic address: Michael.weir@umaryland.edu.
⁸ Volpe Research Center, American Dental Association Foundation, Frederick, MD 21704, USA. Electronic address: sunj@ada.org.
⁹ Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, 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. Electronic address: hxu@umaryland.edu.

PMID: 32526346
DOI: 10.1016/j.jdent.2020.103406

Abstract

Objectives: Polymerization shrinkage stress may lead to marginal damage, microleakage and failure of composite restorations. The objectives of this study were to : (1) develop a novel nanocomposite with low-shrinkage-stress, antibacterial and remineralization properties to reduce marginal enamel demineralization under biofilms; (2) evaluate the mechanical properties of the composite and calcium (Ca) and phosphate (P) ion release; and (3) investigate the cytotoxicity of the new low-shrinkage-stress monomer in vitro.

Methods: The low-shrinkage-stress resin consisted of urethane dimethacrylate (UDMA) and triethylene glycol divinylbenzyl ether (TEG-DVBE), and 3 % dimethylaminohexadecyl methacrylate (DMAHDM) and 20 % calcium phosphate nanoparticles (NACP) were added. Mechanical properties, polymerization shrinkage stress, and degree of conversion were evaluated. The growth of Streptococcus mutans (S. mutans) on enamel slabs with different composites was assessed. Ca and P ion releases and monomer cytotoxicity were measured.

Results: Composite with DMAHDM and NACP had flexural strength of 84.9 ± 10.3 MPa (n = 6), matching that of a commercial control composite. Adding 3 % DMAHDM did not negatively affect the composite ion release. Under S. mutans biofilm, the marginal enamel hardness was 1.2 ± 0.1 GPa for the remineralizing and antibacterial group, more than 2-fold the 0.5 ± 0.07 GPa for control (p < 0.05). The polymerization shrinkage stress of the new composite was 40 % lower than that of traditional composite control (p < 0.05). The new monomers had fibroblast viability similar to that of traditional monomer control (p > 0.1).

Conclusion: A novel low-shrinkage-stress nanocomposite was developed with remineralizing and antibacterial properties. This new composite is promising to inhibit recurrent caries at the restoration margins by reducing polymerization stress and protecting enamel hardness.

Keywords: Biofilm; Calcium phosphate nanoparticles; Enamel remineralization; Low-shrinkage-stress composite; Monomers cytotoxicity; Polymerization stress.

Publication types

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

MeSH terms

Anti-Bacterial Agents / pharmacology
Biofilms*
Calcium Phosphates / pharmacology
Composite Resins / pharmacology
Dental Enamel
Methacrylates / pharmacology
Nanocomposites*
Streptococcus mutans

Substances

Anti-Bacterial Agents
Calcium Phosphates
Composite Resins
Methacrylates