Novel dental adhesive with triple benefits of calcium phosphate recharge, protein-repellent and antibacterial functions

Xianju Xie; Lin Wang; Dan Xing; Ke Zhang; Michael D Weir; Huaibing Liu; Yuxing Bai; Hockin H K Xu

doi:10.1016/j.dental.2017.03.002

Novel dental adhesive with triple benefits of calcium phosphate recharge, protein-repellent and antibacterial functions

Dent Mater. 2017 May;33(5):553-563. doi: 10.1016/j.dental.2017.03.002. Epub 2017 Mar 27.

Authors

Xianju Xie¹, Lin Wang², Dan Xing³, Ke Zhang¹, Michael D Weir⁴, Huaibing Liu⁵, Yuxing Bai⁶, Hockin H K Xu⁷

Affiliations

¹ Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing, China; Department of Endodontics, Periodontics and Prosthodontics, University of Maryland Dental School, Baltimore, MD 21201, USA.
² Department of Endodontics, Periodontics and Prosthodontics, University of Maryland Dental School, Baltimore, MD 21201, USA; VIP Integrated Department, Stomatological Hospital of Jilin University, Changchun, China.
³ Department of Endodontics, Periodontics and Prosthodontics, University of Maryland Dental School, Baltimore, MD 21201, USA; Department of Dentistry, China Rehabilitation Research Center, Beijing, China.
⁴ Department of Endodontics, Periodontics and Prosthodontics, University of Maryland Dental School, Baltimore, MD 21201, USA.
⁵ L.D. Caulk Division, Dentsply Sirona Restorative, Milford, DE 19963, USA.
⁶ Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing, China. Electronic address: byuxing@263.net.
⁷ Department of Endodontics, Periodontics and Prosthodontics, 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; Department of Mechanical Engineering, University of Maryland, Baltimore County, MD 21250, USA. Electronic address: hxu@umaryland.edu.

PMID: 28356216
DOI: 10.1016/j.dental.2017.03.002

Abstract

Objective: A new adhesive containing nanoparticles of amorphous calcium phosphate (NACP) with calcium (Ca) and phosphate (P) ion rechargeability was recently developed; however, it was not antibacterial. The objectives of this study were to: (1) develop a novel adhesive with triple benefits of Ca and P ion recharge, protein-repellent and antibacterial functions via dimethylaminohexadecyl methacrylate (DMAHDM) and 2-methacryloyloxyethyl phosphorylcholine (MPC); and (2) investigate dentin bond strength, protein adsorption, Ca and P ion concentration, microcosm biofilm response and pH properties.

Methods: MPC, DMAHDM and NACP were mixed into a resin consisting of ethoxylated bisphenol A dimethacrylate (EBPADMA), pyromellitic glycerol dimethacrylate (PMGDM), 2-hydroxyethyl methacrylate (HEMA) and bisphenol A glycidyl dimethacrylate (BisGMA). Protein adsorption was measured using a micro bicinchoninic acid method. A human saliva microcosm biofilm model was tested on resins. Colony-forming units (CFU), live/dead assay, metabolic activity, Ca and P ion concentration and biofilm culture medium pH were determined.

Results: The adhesive with 5% MPC+5% DMAHDM+30% NACP inhibited biofilm growth, reducing biofilm CFU by 4 log, compared to control (p<0.05). Dentin shear bond strengths were similar (p>0.1). Biofilm medium became a Ca and P ion reservoir having ion concentration increasing with NACP filler level. The adhesive with 5% MPC+5% DMAHDM+30% NACP maintained a safe pH>6, while commercial adhesive had a cariogenic pH of 4.

Significance: The new adhesive with triple benefits of Ca and P ion recharge, protein-repellent and antibacterial functions substantially reduced biofilm growth, reducing biofilm CFU by 4 orders of magnitude, and yielding a much higher pH than commercial adhesive. This novel adhesive is promising to protect tooth structures from biofilm acids. The method of using NACP, MPC and DMAHDM is promising for application to other dental materials to combat caries.

Keywords: Antibacterial; Calcium phosphate nanoparticles; Caries inhibition; Dental adhesive; Human saliva microcosm biofilm; Protein repellent.

MeSH terms

Anti-Bacterial Agents*
Biofilms
Calcium Phosphates*
Dental Cements*
Humans
Methacrylates
Nanoparticles
Phosphorylcholine / analogs & derivatives

Substances

Anti-Bacterial Agents
Calcium Phosphates
Dental Cements
Methacrylates
Phosphorylcholine
2-methacryloyloxyethyl phosphorylcholine
hydroxyethyl methacrylate