title: Strength and fluoride release characteristics of a calcium fluoride based dental nanocomposite.
abstract: Secondary caries and restoration fracture remain the two most common problems in restorative dentistry. Release of fluoride ions (F) could be a substantial benefit because F could enrich neighboring enamel or dentin to combat caries. The objective of this study was to incorporate novel CaF(2) nanoparticles into dental resin to develop stress-bearing, F-releasing nanocomposite. CaF(2) nanoparticles, prepared in our laboratories for the first time, were combined with reinforcing whisker fillers in a resin. Flexural strength (mean+/-sd; n=6) was 110+/-11 MPa for the composite containing 30% CaF(2) and 35% whiskers by mass. It matched the 108+/-19 MPa of a stress-bearing, non-releasing commercial composite (Tukey's at 0.05). The composite containing 20% CaF(2) had a cumulative F release of 2.34+/-0.26 mmol/L at 10 weeks. The initial F release rate was 2 microg/(hcm(2)), and the sustained release rate after 10 weeks was 0.29 microg/(hcm(2)). These values exceeded the reported releases of traditional and resin-modified glass ionomer materials. In summary, nanocomposites were developed with relatively high strength as well as sustained release of fluoride ions, a combination not available in current materials. These strong and F-releasing composites may yield restorations that can reduce the occurrence of both secondary caries and restoration fracture.
authors: Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, 650 West Baltimore Street, Baltimore, MD 21201, USA. hxu@umaryland.edu
authors: Hockin H K
authors: HH
authors: Xu
authors: Jennifer L
authors: JL
authors: Moreau
authors: Limin
authors: L
authors: Sun
authors: Laurence C
authors: LC
authors: Chow
mesh_terms: D002124:Calcium Fluoride / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry*; D008422:Materials Testing; D046529:Microscopy, Electron, Transmission; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D010758:Phosphorus / Q000737:chemistry; D013718:Tensile Strength; D014961:X-Ray Diffraction
chemical_list: D003764:Dental Materials; D010758:Phosphorus; D002124:Calcium Fluoride; D005459:Fluorides