title: Release of monomers from composite dust.
abstract: OBJECTIVE
  Dental personnel are more at risk to develop asthmatic disease, but the exact reason is so far unknown. During abrasive procedures, dental personnel are exposed to nano-sized dust particles released from dental composite. The aim of this study was to investigate whether respirable composite dust may also release monomers.
  
  
  METHODS
  Respirable (<5μm) composite dust was collected and the release of methacrylate monomers and Bisphenol A (BPA) in water and ethanol was evaluated by liquid chromatography/mass spectroscopy (LC-MS/MS). The dust was ultra-morphologically and chemically analyzed by transmission electron microscopy and energy-dispersive X-ray spectroscopy (TEM-EDS).
  
  
  RESULTS
  LC-MS/MS analysis revealed that, irrespective of the type of composite, the respirable fraction of composite dust may release relatively high concentrations of unpolymerized methacrylate monomers, both in water and ethanol. Higher release was observed in ethanol. The endocrine disruptor BPA also emanated from the composite dust particles. TEM showed that most particles were nano-sized, although particle size ranged between 6nm and 5μm with a mode value between 12 and 39nm. Most particles consisted of several filler particles in resin matrix, although single nano-filler particles could also be observed. Elemental analysis by TEM-EDS proved that the particles collected on the filters originated from the dental composites.
  
  
  CONCLUSIONS
  Theoretically, composite dust may function as a vehicle to transport monomers deeply into the respiratory system. The results of this study may shed another light on the increasing incidence of respiratory disease among dental personnel, and more care should be taken to prevent inhalation of composite dust.
  
  
  CONCLUSIONS
  Special care should be taken to prevent inhalation of composite dust, as the dust particles may release methacrylate monomers.
authors.affiliation: KU Leuven BIOMAT, Department of Oral Health Sciences, University of Leuven & Dentistry University Hospitals Leuven, Kapucijnenvoer 7, 3000 Leuven, Belgium.
authors.forename: S M
authors.initials: SM
authors.lastname: Cokic
authors.affiliation: Centre for Environmental and Health, Department of Public Health and Primary Care, University of Leuven, Kapucijnenvoer 35, 3000 Leuven, Belgium.
authors.forename: R C
authors.initials: RC
authors.lastname: Duca
authors.affiliation: Centre for Environmental and Health, Department of Public Health and Primary Care, University of Leuven, Kapucijnenvoer 35, 3000 Leuven, Belgium; IDEWE, External Service for Prevention and Protection at Work, Heverlee, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Godderis
authors.affiliation: Centre for Environmental and Health, Department of Public Health and Primary Care, University of Leuven, Kapucijnenvoer 35, 3000 Leuven, Belgium.
authors.forename: P H
authors.initials: PH
authors.lastname: Hoet
authors.affiliation: Surface and Interface Engineered Materials, Department of Materials Engineering, University of Leuven, Kasteelpark Arenberg 44, 3001 Heverlee, Belgium.
authors.forename: J W
authors.initials: JW
authors.lastname: Seo
authors.affiliation: KU Leuven BIOMAT, Department of Oral Health Sciences, University of Leuven & Dentistry University Hospitals Leuven, Kapucijnenvoer 7, 3000 Leuven, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Van Meerbeek
authors.affiliation: KU Leuven BIOMAT, Department of Oral Health Sciences, University of Leuven & Dentistry University Hospitals Leuven, Kapucijnenvoer 7, 3000 Leuven, Belgium. Electronic address: kirsten.vanlanduyt@med.kuleuven.be.
authors.forename: K L
authors.initials: KL
authors.lastname: Van Landuyt
mesh_terms: D001559:Benzhydryl Compounds / Q000737:chemistry*; D001672:Biocompatible Materials; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000009:adverse effects / Q000737:chemistry* / Q000145:classification; D004391:Dust; D000431:Ethanol / Q000737:chemistry; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000009:adverse effects / Q000737:chemistry / Q000648:ultrastructure; D016273:Occupational Exposure / Q000009:adverse effects; D010316:Particle Size; D010636:Phenols / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D014867:Water / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D001672:Biocompatible Materials; D017438:Bisphenol A-Glycidyl Methacrylate; D003188:Composite Resins; D004391:Dust; D000431:Ethanol; D008689:Methacrylates; D010636:Phenols; D011109:Polymethacrylic Acids; D012822:Silicon Dioxide; D014867:Water; D015040:Zirconium; C474035:Filtek Supreme; C470230:Gradia; C509998:Grandio; C083568:Z100 composite resin; C006780:bisphenol A; D000098826:Bisphenol A Compounds
keywords: Biocompatibility; Dust; Filler; Monomer release; Nanoparticle; Occupational