An antifungal coating for dental silicones composed of chlorhexidine nanoparticles

Sarah J Garner; Angela H Nobbs; Lisa M McNally; Michele E Barbour

doi:10.1016/j.jdent.2014.12.005

An antifungal coating for dental silicones composed of chlorhexidine nanoparticles

J Dent. 2015 Mar;43(3):362-72. doi: 10.1016/j.jdent.2014.12.005. Epub 2014 Dec 13.

Authors

Sarah J Garner¹, Angela H Nobbs², Lisa M McNally³, Michele E Barbour⁴

Affiliations

¹ Oral Nanoscience, School of Oral and Dental Sciences, University of Bristol, Bristol, UK.
² Microbiology, Oral Microbiology, School of Oral and Dental Sciences, University of Bristol, Bristol, UK.
³ Restorative Dentistry, School of Oral and Dental Sciences, University of Bristol, Bristol, UK.
⁴ Oral Nanoscience, School of Oral and Dental Sciences, University of Bristol, Bristol, UK. Electronic address: M.E.Barbour@bristol.ac.uk.

PMID: 25511302
DOI: 10.1016/j.jdent.2014.12.005

Abstract

Objectives: The aims of this study were to synthesise a range of chlorhexidine-containing nanoparticles (CHX-NPs), and investigate the feasibility of using these as an antifungal coating for dental silicones.

Methods: CHX-NPs were precipitated in aqueous reaction by mixing solutions of CHX digluconate with solutions of sodium triphosphate (TP), trimetaphosphate (TMP) or hexametaphosphate (HMP). CHX-NPs were deposited on commercial dental silicones by immersion coating, and these were characterised for hydrophilicity (contact angle) and water uptake (mass change). Soluble CHX elution into artificial saliva was measured using ultraviolet spectrophotometry. Antifungal efficacy against Candida albicans was investigated using a cell proliferation assay.

Results: Coating silicones with CHX-NPs did not significantly affect hydrophilicity, as assessed using water contact angle, or water uptake as assessed by mass change following 16 weeks' immersion in artificial saliva. CHX-NP-coated silicone specimens released soluble CHX into artificial saliva. The salt of CHX and the immersion time affected the rate, concentration and duration of CHX release, with CHX-HMP exhibiting a slow, sustained release and CHX-TP and CHX-TMP exhibiting a faster, more concentrated release. C. albicans metabolic activity was inhibited by presence of CHX-HMP-NPs in suspension.

Conclusions: CHX-NPs provided a localised, controlled dose of soluble CHX at the surface of dental silicones without adversely affecting hydrophilicity or water uptake. CHX-HMP NPs provided effective antifungal control of C. albicans in a cell proliferation assay. Coating materials with these nanoparticles could be an effective way of delivering low, but clinically relevant, concentrations of chlorhexidine in the oral environment.

Clinical significance: Denture stomatitis is a common oral infection and is associated with fungal infestation of denture soft lining and obturator materials, which are often silicones such as those used here. Our study suggests that CHX-NPs may be a useful strategy in design of antifungal coatings for these materials.

Keywords: Candida albicans; Chlorhexidine; Denture; Nanoparticles; Obturator.

Publication types

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

MeSH terms

Antifungal Agents / pharmacology*
Chlorhexidine / pharmacology*
Dental Materials* / chemistry
Denture Liners*
Microbial Sensitivity Tests
Nanoparticles*
Silicones*

Substances

Antifungal Agents
Dental Materials
Silicones
Chlorhexidine