title: Remineralization of demineralized enamel via calcium phosphate nanocomposite.
abstract: Secondary caries remains the main problem limiting the longevity of composite restorations. The objective of this study was to investigate the remineralization of demineralized human enamel in vitro via a nanocomposite containing nanoparticles of amorphous calcium phosphate (NACP). NACP were synthesized by a spray-drying technique and incorporated into a dental resin. First, caries-like subsurface enamel lesions were created via an acidic solution. Then, NACP nanocomposite or a commercial fluoride-releasing control composite was placed on the demineralized enamel, along with control enamel without a composite. These specimens were then treated with a cyclic demineralization/remineralization regimen for 30 days. Quantitative microradiography showed typical enamel subsurface demineralization before cyclic demineralization/remineralization treatment, and significant remineralization in enamel under the NACP nanocomposite after the demineralization/remineralization treatment. The NACP nanocomposite had the highest enamel remineralization (mean ± SD; n = 6) of 21.8 ± 3.7%, significantly higher than the 5.7 ± 6.9% for fluoride-releasing composite (p < 0.05). The enamel group without composite had further demineralization of -26.1 ± 16.2%. In conclusion, a novel NACP nanocomposite was effective in remineralizing enamel lesions in vitro. Its enamel remineralization was 4-fold that of a fluoride-releasing composite control. Combined with the good mechanical and acid-neutralization properties reported earlier, the new NACP nanocomposite is promising for remineralization of demineralized tooth structures.
authors.affiliation: Biomaterials & Tissue Engineering Division, Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland School of Dentistry, Baltimore, MD 21201, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Weir
authors.forename: L C
authors.initials: LC
authors.lastname: Chow
authors.forename: H H K
authors.initials: HH
authors.lastname: Xu
mesh_terms: D000704:Analysis of Variance; D002130:Calcium Phosphates / Q000378:metabolism*; D002327:Cariostatic Agents; D003188:Composite Resins / Q000737:chemistry / Q000627:therapeutic use; D003743:Dental Enamel / Q000378:metabolism*; D005459:Fluorides; D006801:Humans; D008689:Methacrylates; D008852:Microradiography; D053761:Nanocomposites / Q000737:chemistry* / Q000627:therapeutic use; D010795:Phthalic Acids; D011092:Polyethylene Glycols; D011109:Polymethacrylic Acids; D017001:Tooth Demineralization / Q000628:therapy*; D014089:Tooth Remineralization / Q000379:methods*; D015018:Ytterbium
chemical_list: D002130:Calcium Phosphates; D002327:Cariostatic Agents; D003188:Composite Resins; D008689:Methacrylates; D010795:Phthalic Acids; D011109:Polymethacrylic Acids; C519480:amorphous calcium phosphate; C102799:ytterbium fluoride; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; C074277:ethoxylated bis-phenol A dimethacrylate; C005044:hydroxyethyl methacrylate; D015018:Ytterbium; D005459:Fluorides