One-year water-ageing of calcium phosphate composite containing nano-silver and quaternary ammonium to inhibit biofilms.
Dental composites are commonly used restorative materials; however, secondary caries due to biofilm acids remains a major problem. The objectives of this study were (1) to develop a composite containing quaternary ammonium dimethacrylate (QADM), nanoparticles of silver (NAg), and nanoparticles of amorphous calcium phosphate (NACP), and (2) to conduct the first investigation of the mechanical properties, biofilm response and acid production vs water-ageing time from 1 day to 12 months. A 4 × 5 design was utilized, with four composites (NACP-QADM composite, NACP-NAg composite, NACP-QADM-NAg composite, and a commercial control composite), and five water-ageing time periods (1 day, and 3, 6, 9, and 12 months). After each water-ageing period, the mechanical properties of the resins were measured in a three-point flexure, and antibacterial properties were tested via a dental plaque biofilm model using human saliva as an inoculum. After 12 months of water-ageing, NACP-QADM-NAg had a flexural strength and elastic modulus matching those of the commercial control (P>0.1). Incorporation of QADM or NAg into the NACP composite greatly reduced biofilm viability, metabolic activity and acid production. A composite containing both QADM and NAg possessed a stronger antibacterial capability than one with QADM or NAg alone (P<0.05). The anti-biofilm activity was maintained after 12 months of water-ageing and showed no significant decrease with increasing time (P>0.1). In conclusion, the NACP-QADM-NAg composite decreased biofilm viability and lactic acid production, while matching the load-bearing capability of a commercial composite. There was no decrease in its antibacterial properties after 1 year of water-ageing. The durable antibacterial and mechanical properties indicate that NACP-QADM-NAg composites may be useful in dental restorations to combat caries.
State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China.|Biomaterials and Tissue Engineering Division, Department of Endodontics, Periodontics and Prosthodontics, University of Maryland School of Dentistry, Baltimore, USA.
Lei
L
Cheng
Biomaterials and Tissue Engineering Division, Department of Endodontics, Periodontics and Prosthodontics, University of Maryland School of Dentistry, Baltimore, USA.|Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing, China.
Ke
K
Zhang
State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China.|Biomaterials and Tissue Engineering Division, Department of Endodontics, Periodontics and Prosthodontics, University of Maryland School of Dentistry, Baltimore, USA.
Chen-Chen
CC
Zhou
Biomaterials and Tissue Engineering Division, Department of Endodontics, Periodontics and Prosthodontics, University of Maryland School of Dentistry, Baltimore, USA.
Michael D
MD
Weir
State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China.
Xue-Dong
XD
Zhou
Biomaterials and Tissue Engineering Division, Department of Endodontics, Periodontics and Prosthodontics, University of Maryland School of Dentistry, Baltimore, USA.|Center for Stem Cell Biology and Regenerative Medicine, University of Maryland School of Medicine, Baltimore, USA.|Department of Mechanical Engineering, University of Maryland, Baltimore County, USA.
Hockin H K
HH
Xu
D064751:Ammonium Compounds; D000900:Anti-Bacterial Agents; D018441:Biofilms; D002130:Calcium Phosphates; D003188:Composite Resins; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates; D000644:Quaternary Ammonium Compounds; D012834:Silver; D014867:Water
D064751:Ammonium Compounds; D000900:Anti-Bacterial Agents; D002130:Calcium Phosphates; D003188:Composite Resins; D008689:Methacrylates; D000644:Quaternary Ammonium Compounds; D014867:Water; D012834:Silver