title: [Effect of microwave plasma parameters on the surface modification of denture base resins].
abstract: OBJECTIVE
  To explore the working parameters of the microwave plasma for surface modification of denture base resins.
  
  
  METHODS
  Using orthogonal test method, 80 specimens of denture material were divided into 16 groups for testing. At the gas flow of 13.7 cm3/min, the specimens were tested under the working condition of different microwave powers (100, 150, 200 and 250 W), different gasses (oxygen, air, argon, oxygen and argon mixture), different gas pressure (0.4, 0.6, 0.8, and 1 kPa), and varying processing time (1, 2, 5, and 8 min). Each group of specimens was treated with the microwave plasma and the contact angles were confirmed by scanning electron microscopy.
  
  
  RESULTS
  The pictures of instantaneous droplet morphology were obtained from each group of samples, and the values of contact angle were measured. The contact angle was 68.86 degrees in the untreated group, and the angles of several treated groups were 48.15 degrees , 40.7 degrees and 32.76 degrees, showing a statistically significant variation of the contact angle after the treatment.
  
  
  CONCLUSIONS
  Processing time of 8 min, microwave power at 100 W, total pressure in the chamber at 0.8 kPa, and the presence of oxygen constitute the optimal condition of microwave plasma for surface modification of denture base resins. Under these conditions, the smallest contact angle of the denture base resins is 34.58 degrees, suggesting a good effect of surface modification.
authors.affiliation: Department of Prosthetics, School of Stamatology, Wuhan University, Wuhan 430079, China. 18907123599@189.cn
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Hui-yong
authors.initials: HY
authors.lastname: Xu
authors.forename: Wei-dong
authors.initials: WD
authors.lastname: Zhao
authors.forename: Xiang-yong
authors.initials: XY
authors.lastname: Cheng
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry* / Q000528:radiation effects; D003819:Denture Bases; D008422:Materials Testing; D008872:Microwaves; D013499:Surface Properties
chemical_list: D000180:Acrylic Resins