title: Surface modification of several dental substrates by non-thermal, atmospheric plasma brush.
abstract: OBJECTIVE
  The purpose of this study was to reveal the effectiveness of non-thermal atmospheric plasma brush in surface wettability and modification of four dental substrates.
  
  
  METHODS
  Specimens of dental substrates including dentin, enamel, and two composites Filtek Z250, Filtek LS Silorane were prepared (∼2mm thick, ∼10mm diameter). The prepared surfaces were treated for 5-45s with a non-thermal atmospheric plasma brush working at temperatures from 36 to 38°C. The plasma-treatment effects on these surfaces were studied with contact-angle measurement, X-ray photoemission spectroscopy (XPS) and scanning electron microscopy (SEM).
  
  
  RESULTS
  The non-thermal atmospheric argon plasma brush was very efficient in improving the surface hydrophilicity of four substrates studied. The results indicated that water contact angle values decreased considerably after only 5s plasma treatment of all these substrates. After 30s treatment, the values were further reduced to <5°, which was close to a value for super hydrophilic surfaces. XPS analysis indicated that the percent of elements associated with mineral in dentin/enamel or fillers in the composites increased. In addition, the percent of carbon (%C) decreased while %O increased for all four substrates. As a result, the O/C ratio increased dramatically, suggesting that new oxygen-containing polar moieties were formed on the surfaces after plasma treatment. SEM surface images indicated that no significant morphology change was induced on these dental substrates after exposure to plasmas.
  
  
  CONCLUSIONS
  Without affecting the bulk properties, a super-hydrophilic surface could be easily achieved by the plasma brush treatment regardless of original hydrophilicity/hydrophobicity of dental substrates tested.
authors.affiliation: Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri-Kansas City, Kansas City, MO 64108, USA.
authors.forename: Mingsheng
authors.initials: M
authors.lastname: Chen
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: M
authors.initials: M
authors.lastname: Sky Driver
authors.forename: Anthony N
authors.initials: AN
authors.lastname: Caruso
authors.forename: Qingsong
authors.initials: Q
authors.lastname: Yu
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
mesh_terms: D001128:Argon / Q000737:chemistry; D002244:Carbon / Q000032:analysis; D003188:Composite Resins / Q000737:chemistry*; D055117:Curing Lights, Dental / Q000145:classification; D003743:Dental Enamel / Q000648:ultrastructure*; D003804:Dentin / Q000648:ultrastructure*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010100:Oxygen / Q000032:analysis; D056951:Photoelectron Spectroscopy; D058626:Plasma Gases / Q000737:chemistry*; D058105:Polymerization; D062047:Silorane Resins / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D017155:Wettability
chemical_list: D003188:Composite Resins; C444701:Filtek Z250; D058626:Plasma Gases; D062047:Silorane Resins; C555513:silorane composite resin; D001128:Argon; D002244:Carbon; D010100:Oxygen
keywords: Composites; Contact angle; Dental surfaces; Non-thermal plasmas; Wettability