Polymeric nanoparticles protect the resin-dentin bonded interface from cariogenic biofilm degradation

Manuel Toledano-Osorio; Raquel Osorio; Fátima S Aguilera; Antonio Luis Medina-Castillo; Manuel Toledano; Estrella Osorio; Sergio Acosta; Ruoqiong Chen; Conrado Aparicio

doi:10.1016/j.actbio.2020.05.002

Polymeric nanoparticles protect the resin-dentin bonded interface from cariogenic biofilm degradation

Acta Biomater. 2020 Jul 15:111:316-326. doi: 10.1016/j.actbio.2020.05.002. Epub 2020 May 19.

Authors

Manuel Toledano-Osorio¹, Raquel Osorio¹, Fátima S Aguilera¹, Antonio Luis Medina-Castillo², Manuel Toledano³, Estrella Osorio¹, Sergio Acosta⁴, Ruoqiong Chen⁵, Conrado Aparicio⁶

Affiliations

¹ University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, 18071, Granada, Spain.
² University of Granada, NanoMyP. Spin-Off Enterprise, Edificio BIC-Granada. Av. Innovación 1, 18016, Armilla, Granada, Spain.
³ University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, 18071, Granada, Spain. Electronic address: toledano@ugr.es.
⁴ Bioforge lab, CIBER-BBN, Edificio LUCIA, University of Valladolid, Paseo Belen 19, Valladolid 47011, Spain.
⁵ Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, USA.
⁶ MDRCBB-Minnesota Dental Research Center for Biomaterials and Biomechanics, Department of Restorative Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, USA.

PMID: 32439613
DOI: 10.1016/j.actbio.2020.05.002

Abstract

The objective was to assess doxycycline (Dox) and zinc (Zn) doped nanoparticles' (NPs) potential to protect the resin-dentin interface from cariogenic biofilm. Three groups of polymeric NPs were tested: unloaded, loaded with zinc and with doxycycline. NPs were applied after dentin etching. The disks were exposed to a cariogenic biofilm challenge in a Drip-Flow Reactor during 72 h and 7 d. Half of the specimens were not subjected to biofilm formation but stored 72 h and 7 d. LIVE/DEAD® viability assay, nano-dynamic mechanical assessment, Raman spectroscopy and field emission electron microscopy (FESEM) analysis were performed. The measured bacterial death rates, at 7 d were 46% for the control group, 51% for the undoped-NPs, 32% for Dox-NPs, and 87% for Zn-NPs; being total detected bacteria reduced five times in the Dox-NPs group. Zn-NPs treated samples reached, in general, the highest complex modulus values at the resin-dentin interface over time. Regarding the mineral content, Zn-NPs-treated dentin interfaces showed the highest mineralization degree associated to the phosphate peak and the relative mineral concentration. FESEM images after Zn-NPs application permitted to observe remineralization of the etched and non-resin infiltrated collagen layer, and bacteria were scarcely encountered. The combined antibacterial and remineralizing effects, when Zn-NPs were applied, reduced biofilm formation. Dox-NPs exerted an antibacterial role but did not remineralize the bonded interface. Undoped-NPs did not improve the properties of the interfaces. Application of Zn-doped NPs during the bonding procedure is encouraged. STATEMENT OF SIGNIFICANCE: Application of Zn-doped nanoparticles on acid etched dentin reduced biofilm formation and viability at the resin-dentin interface due to both remineralization and antibacterial properties. Doxycycline-doped nanoparticles also diminished oral biofilm viability, but did not remineralize the resin-dentin interface.

Keywords: Biofilm; Degradation; Dentin; Interface; Nanoparticle.

Publication types

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

MeSH terms

Biofilms
Dental Bonding*
Dentin
Dentin-Bonding Agents / pharmacology
Materials Testing
Nanoparticles*
Polymers
Resin Cements / pharmacology
Tensile Strength
Zinc

Substances

Dentin-Bonding Agents
Polymers
Resin Cements
Zinc