Development of a novel antimicrobial-releasing glass ionomer cement functionalized with chlorhexidine hexametaphosphate nanoparticles.
BACKGROUND
Glass ionomer cements (GICs) are a class of dental biomaterials. They have a wide range of uses including permanent restorations (fillings), cavity linings, fissure sealants and adhesives. One of the most common reasons for replacing a dental restoration is recurrent bacterial tooth decay around the margins of the biomaterial. Therefore, a dental biomaterial which creates a sustained antimicrobial environment around the restoration would be of considerable clinical benefit. In this manuscript, the formulation of a GIC containing novel antimicrobial nanoparticles composed of chlorhexidine hexametaphosphate at 1, 2, 5, 10 and 20% powder substitution by mass is reported. The aim is to create GICs which contain chlorhexidine-hexametaphosphate nanoparticles and characterize the nanoparticle size, morphology and charge and the release of chlorhexidine and fluoride, tensile strength and morphology of the GICs.


RESULTS
The GICs released chlorhexidine, which is a broad spectrum antimicrobial agent effective against a wide range of oral bacteria, over the duration of the experiment in a dose-dependent manner. This was not at the expense of other properties; fluoride release was not significantly affected by the substitution of antimicrobial nanoparticles in most formulations and internal structure appeared unaffected up to and including 10% substitution. Diametral tensile strength decreased numerically with substitutions of 10 and 20% nanoparticles but this difference was not statistically significant.


CONCLUSIONS
A series of GICs functionalized with chlorhexidine-hexametaphosphate nanoparticles were created for the first time. These released chlorhexidine in a dose-dependent manner. These materials may find application in the development of a new generation of antimicrobial dental nanomaterials.
Edward R
ER
Hook
Olivia J
OJ
Owen
Candice A
CA
Bellis
James A
JA
Holder
Dominic J
DJ
O'Sullivan
Oral Nanoscience, School of Oral and Dental Sciences, University of Bristol, Lower Maudlin St, Bristol, BS1 2LY, UK. m.e.barbour@bristol.ac.uk.
Michele E
ME
Barbour
D000891:Anti-Infective Agents, Local / Q000008:administration & dosage* / Q000737:chemistry; D002710:Chlorhexidine / Q000008:administration & dosage* / Q000737:chemistry; D005459:Fluorides / Q000008:administration & dosage* / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry*; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010710:Phosphates / Q000737:chemistry*; D013718:Tensile Strength
D000891:Anti-Infective Agents, Local; D005899:Glass Ionomer Cements; D010710:Phosphates; C005035:hexametaphosphate; D005459:Fluorides; D002710:Chlorhexidine