Novel rechargeable calcium phosphate nanocomposite with antibacterial activity to suppress biofilm acids and dental caries

Yousif A Al-Dulaijan; Lei Cheng; Michael D Weir; Mary Anne S Melo; Huaibing Liu; Thomas W Oates; Lin Wang; Hockin H K Xu

doi:10.1016/j.jdent.2018.03.003

Novel rechargeable calcium phosphate nanocomposite with antibacterial activity to suppress biofilm acids and dental caries

J Dent. 2018 May:72:44-52. doi: 10.1016/j.jdent.2018.03.003. Epub 2018 Mar 8.

Authors

Yousif A Al-Dulaijan¹, Lei Cheng², Michael D Weir³, Mary Anne S Melo³, Huaibing Liu⁴, Thomas W Oates³, Lin Wang⁵, Hockin H K Xu⁶

Affiliations

¹ Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman bin Faisal University, Dammam, Saudi Arabia.
² Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China.
³ Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA.
⁴ L.D. Caulk Division, Dentsply Sirona Restorative, Milford, DE 19963, USA.
⁵ Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; VIP Integrated Department, Stomatological Hospital of Jilin University, Changchun, China. Electronic address: dentistwanglin@126.com.
⁶ 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: 29526668
DOI: 10.1016/j.jdent.2018.03.003

Abstract

Objective: Rechargeable calcium phosphate (CaP) composites were developed recently. However, none of the rechargeable CaP composites was antibacterial. The objectives of this study were to develop the first rechargeable CaP composite that was antibacterial, and to investigate the effects of adding dimethylaminohexadecyl methacrylate (DMAHDM) into rechargeable CaP composite on ion rechargeability and re-release as well as biofilm properties.

Methods: DMAHDM was synthesized via a Menschutkin reaction. Nanoparticles of amorphous calcium phosphate (NACP) were synthesized using a spray-drying technique. The resin contained ethoxylated bisphenol A dimethacrylate (EBPADMA) and pyromellitic glycerol dimethacrylate (PMGDM). Two composites were fabricated: rechargeable NACP composite, and rechargeable NACP-DMAHDM composite. Mechanical properties and ion release and recharge were measured. A dental plaque microcosm biofilm model using saliva was tested.

Results: Flexural strength and elastic modulus of rechargeable NACP and NACP-DMAHDM composites matched commercial control composite (p > 0.1). NACP-DMAHDM inhibited biofilm metabolic activity and lactic acid, and reduced biofilm colony-forming units (CFU) by 3-4 log. NACP and NACP-DMAHDM showed similar Ca and P ion recharge and re-release (p > 0.1). Therefore, adding DMAHDM did not compromise the ion rechargeability. One recharge yielded continuous release for 42 d. The release was maintained at the same level with increasing number of recharge cycles, indicating long-term ion release and remineralization capability.

Conclusions: The first CaP rechargeable and antibacterial composite was developed. Adding DMAHDM into the rechargeable NACP composite did not adversely affect the Ca and P ion release and recharge, and the composite had much less biofilm growth and lactic acid production, with CFU reduction by 3-4 log.

Clinical significance: This novel CaP rechargeable composite with long-term remineralization and antibacterial properties is promising for tooth restorations to inhibit caries.

Keywords: Antibacterial; Calcium phosphate nanoparticles; Dental composite; Long-term ion recharge; Oral biofilms; Remineralization.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Anti-Bacterial Agents / pharmacology*
Benzhydryl Compounds / pharmacology
Benzoates
Biofilms / drug effects*
Calcium Phosphates / pharmacology*
Camphor / analogs & derivatives
Camphor / pharmacology
Colony Count, Microbial
Composite Resins / pharmacology
Dental Caries / drug therapy*
Dental Plaque / microbiology
Humans
Lactic Acid / metabolism
Materials Testing
Methacrylates / pharmacology
Nanocomposites / chemistry*
Nanoparticles / chemistry
Saliva
Tooth Remineralization
para-Aminobenzoates / pharmacology

Substances

Anti-Bacterial Agents
Benzhydryl Compounds
Benzoates
Calcium Phosphates
Composite Resins
Methacrylates
ethyl 4-N,N-dimethylaminobenzoate
para-Aminobenzoates
Lactic Acid
ethoxylated bis-phenol A dimethacrylate
Camphor
2,2-di(4-methacryloxyphenyl)propane
pyromellitic acid
camphorquinone