title: Time-related wettability characteristic of acrylic resin surfaces treated by glow discharge.
abstract: BACKGROUND
  Adhesion and cohesion have important roles in denture retention, and attempts have been made to improve the wettability of the acrylic resin material by surface treatments.
  
  
  OBJECTIVE
  This study examined the initial and subsequent wettability of an acrylic resin denture base material treated under air or argon plasma atmosphere before and after exposure to air or distilled water.
  
  
  METHODS
  Acrylic resin specimens were treated with plasma under air or argon atmosphere and were either exposed to air or distilled water for up to 60 days. Wettability characteristics of the acrylic resin specimens were determined by contact-angle measurements after 2 hours and after 60 days. Surface composition of the specimens also was analyzed with x-ray photoelectron spectroscopic (XPS) measurements.
  
  
  RESULTS
  Statistically significant difference was found between control and each of the plasma treatment groups (P <.05). Although the storage condition and storage period caused statistically significant difference on contact angle values (P <.05), atmosphere type did not have any effect on the results (P >.05). XPS spectra of the plasma-treated specimens differed from control specimens only in the O1s region with a narrower and more intense peak that could be assigned to -COH groups. During 60 days of exposure, the O/C atomic ratios decreased within the first 2 weeks but settled to 0.40 and 0. 32 up to 60 days compared with 0.26 for untreated control specimens.
  
  
  CONCLUSIONS
  Glow discharge plasma altered the surfaces of the acrylic resin and increased thc wettability as shown both by XPS and contact-angle measurements, and plasma treatment seemed to offer a durable (at least up to 60 days) wettability.
authors.affiliation: Faculty of Dentistry, Ankara University, Ankara, Turkey.
authors.forename: N
authors.initials: N
authors.lastname: Ozden
authors.forename: F
authors.initials: F
authors.lastname: Akaltan
authors.forename: S
authors.initials: S
authors.lastname: Suzer
authors.forename: G
authors.initials: G
authors.lastname: Akovali
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000268:Adhesiveness; D000388:Air; D000704:Analysis of Variance; D001128:Argon; D003819:Denture Bases; D004563:Electrochemistry; D004577:Electron Probe Microanalysis; D008422:Materials Testing; D013997:Time Factors; D017155:Wettability
chemical_list: D000180:Acrylic Resins; D001128:Argon