title: [Surface modification of dental alumina ceramic with silica coating].
abstract: OBJECTIVE
  To make silica coating through sol-gel process, and to evaluate the wettability of dental alumina ceramic with or without coating.
  
  
  METHODS
  Silica coating was prepared with colloidal silica sol on In-Ceram alumina ceramic surface which had been treated with air particle abrasion. Coating gel after heat treatment was observed with atomic force microscope (AFM), and was analyzed by infrared spectrum (IR) with gel without sintered as control. Contact angles of oleic acid to be finished, sandblasted and coated ceramic surface of were measured.
  
  
  RESULTS
  AFM pictures showed that some parts of nano-particles in coating gel conglomerated after heat treatment. It can be seen from the IR picture that bending vibration absorption kurtosis of Si-OH also vanished after heat treatment. Among contact angles of three treated surface, the ones on polished surface were the biggest (P = 0.000, P = 0.000), and sandblasting+silica coating surface the smallest (P = 0.000, P = 0.003).
  
  
  CONCLUSIONS
  Silica coating can be made with sol-gel process successfully. Heat treatment may reinforce Si-O-Si net structure of coating gel. Wettability of dental alumina ceramic with silica coating is higher than with sandblasting and polishing.
authors.affiliation: Dept. of Prosthetic, School of Stomatology, Nanjing Medical University, Nanjing 210029, China.
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Xie
authors.forename: Fei-Min
authors.initials: FM
authors.lastname: Zhang
authors.forename: Xiao-Zu
authors.initials: XZ
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Xia
mesh_terms: D000537:Aluminum Oxide; D002516:Ceramics; D001840:Dental Bonding; D003776:Dental Porcelain; D008422:Materials Testing; D012822:Silicon Dioxide; D013499:Surface Properties
chemical_list: C483026:In-Ceram Alumina; D003776:Dental Porcelain; D012822:Silicon Dioxide; D000537:Aluminum Oxide