title: Regulation of NaF release from bis-GMA/TEGDMA resin using gamma-methacryloxypropyltrimethoxysilane.
abstract: OBJECTIVE
  The aim of this study was to evaluate the feasibility of regulation of NaF release from bis-GMA/TEGDMA resin using gamma-methacryloxypropyltrimethoxysilane (gamma-MPTS).
  
  
  METHODS
  NaF powder was treated with gamma-MPTS to form a polysiloxane layer on its surface. The morphology and the composition of the NaF powder treated with gamma-MPTS were evaluated using scanning electron microscopy, infrared spectroscopy, contact angle measurement and X-ray photoelectron spectroscopy. Bis-GMA/TEGDMA resin containing 50 wt% NaF powder was prepared as a model resin and immersed in distilled water at 37 degrees C, and the amount of fluoride released from the resin was measured using a fluoride electrode. The mechanical strength in terms of diametral tensile strength before and after fluoride release was also measured, and statistically analyzed using one-way factorial ANOVA and Fisher's PLSD method.
  
  
  RESULTS
  NaF powder was covered with hydrophobic gamma-MPTS delivered polysiloxane. A larger amount of fluoride was released at the initial stage from the resin containing NaF treated with no gamma-MPTS. However, fluoride release terminated in a relatively shorter period. In contrast, we observed a smaller amount of fluoride released for a longer period from the resin containing NaF treated with gamma-MPTS.
  
  
  CONCLUSIONS
  We found that gamma-MPTS treatment is useful for the regulation of NaF release from bis-GMA/TEGDMA resin. The mechanism of slow NaF release may be the formation of a hydrophobic polysiloxane layer on the surface of NaF powder and resulting slow water diffusion to NaF powder.
authors.affiliation: Department of Operative Dentistry, Okayama University Dental School, Okayama, Japan. nakabo@dent.okayama-u.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakabo
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Torii
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Itota
authors.forename: Kunio
authors.initials: K
authors.lastname: Ishikawa
authors.forename: Kazuomi
authors.initials: K
authors.lastname: Suzuki
mesh_terms: D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry*; D002327:Cariostatic Agents / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry*; D004058:Diffusion; D004577:Electron Probe Microanalysis; D005240:Feasibility Studies; D006801:Humans; D006813:Humidity; D007101:Immersion; D017736:Ion-Selective Electrodes; D008689:Methacrylates / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry*; D011208:Powders; D012821:Silanes / Q000737:chemistry*; D012833:Siloxanes / Q000737:chemistry; D012969:Sodium Fluoride / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared; D013223:Statistics as Topic; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D014867:Water / Q000737:chemistry; D017155:Wettability
chemical_list: D002327:Cariostatic Agents; D003188:Composite Resins; D008689:Methacrylates; D011109:Polymethacrylic Acids; D011208:Powders; D012821:Silanes; D012833:Siloxanes; D014867:Water; C020946:triethylene glycol dimethacrylate; C017492:methacryloxypropyltrimethoxysilane; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; D012969:Sodium Fluoride