Do Dental Resin Composites Accumulate More Oral Biofilms and Plaque than Amalgam and Glass Ionomer Materials?

Ning Zhang; Mary A S Melo; Michael D Weir; Mark A Reynolds; Yuxing Bai; Hockin H K Xu

doi:10.3390/ma9110888

Do Dental Resin Composites Accumulate More Oral Biofilms and Plaque than Amalgam and Glass Ionomer Materials?

Materials (Basel). 2016 Nov 1;9(11):888. doi: 10.3390/ma9110888.

Authors

Ning Zhang^{1

2}, Mary A S Melo³, Michael D Weir⁴, Mark A Reynolds⁵, Yuxing Bai⁶, Hockin H K Xu^{7

8

9

10}

Affiliations

¹ Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing 100050, China. dentistzhang112@163.com.
² Department of Endodontics, Periodontics and Prosthodontics, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA. dentistzhang112@163.com.
³ Department of Endodontics, Periodontics and Prosthodontics, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA. mmelo@umaryland.edu.
⁴ Department of Endodontics, Periodontics and Prosthodontics, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA. MWeir@umaryland.edu.
⁵ Department of Endodontics, Periodontics and Prosthodontics, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA. MReynolds@umaryland.edu.
⁶ Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing 100050, China. byuxing@263.net.
⁷ Department of Endodontics, Periodontics and Prosthodontics, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA. hxu@umaryland.edu.
⁸ Center for Stem Cell Biology & Regenerative Medicine, School of Medicine, University of Maryland, Baltimore, MD 21201, USA. hxu@umaryland.edu.
⁹ Marlene and Stewart Greenebaum Cancer Center, School of Medicine, University of Maryland, Baltimore, MD 21201, USA. hxu@umaryland.edu.
¹⁰ Department of Mechanical Engineering, University of Maryland, Baltimore, MD 21250, USA. hxu@umaryland.edu.

Abstract

A long-time drawback of dental composites is that they accumulate more biofilms and plaques than amalgam and glass ionomer restorative materials. It would be highly desirable to develop a new composite with reduced biofilm growth, while avoiding the non-esthetics of amalgam and low strength of glass ionomer. The objectives of this study were to: (1) develop a protein-repellent composite with reduced biofilms matching amalgam and glass ionomer for the first time; and (2) investigate their protein adsorption, biofilms, and mechanical properties. Five materials were tested: A new composite containing 3% of protein-repellent 2-methacryloyloxyethyl phosphorylcholine (MPC); the composite with 0% MPC as control; commercial composite control; dental amalgam; resin-modified glass ionomer (RMGI). A dental plaque microcosm biofilm model with human saliva as inoculum was used to investigate metabolic activity, colony-forming units (CFU), and lactic acid production. Composite with 3% MPC had flexural strength similar to those with 0% MPC and commercial composite control (p > 0.1), and much greater than RMGI (p < 0.05). Composite with 3% MPC had protein adsorption that was only 1/10 that of control composites (p < 0.05). Composite with 3% MPC had biofilm CFU and lactic acid much lower than control composites (p < 0.05). Biofilm growth, metabolic activity and lactic acid on the new composite with 3% MPC were reduced to the low level of amalgam and RMGI (p > 0.1). In conclusion, a new protein-repellent dental resin composite reduced oral biofilm growth and acid production to the low levels of non-esthetic amalgam and RMGI for the first time. The long-held conclusion that dental composites accumulate more biofilms than amalgam and glass ionomer is no longer true. The novel composite is promising to finally overcome the major biofilm-accumulation drawback of dental composites in order to reduce biofilm acids and secondary caries.

Keywords: amalgam; caries inhibition; dental composite; glass ionomer; human saliva microcosm biofilm; protein repellant.

Grants and funding

R01 DE017974/DE/NIDCR NIH HHS/United States