title: Chlorhexidine Uptake and Release From Modified Titanium Surfaces and Its Antimicrobial Activity.
abstract: BACKGROUND
  Decontamination by adjunctive antiseptic agents such as chlorhexidine (CHX) is often recommended for the treatment of peri-implant infections. However, its action on the titanium implant surface needs further research. This study is designed to evaluate the ability of modified titanium surfaces to release chlorhexidine after periodic CHX exposure.
  
  
  METHODS
  Four titanium surfaces were prepared: 1) no surface treatment control (machined surface [MA]); 2) an acid mix of 10% HNO3 and 5% HF (HNF); 3) resorbable blast media (RBM); and 4) sandblasting and acid etching (SLA). Each surface was analyzed using a confocal laser scanning microscope and a scanning electron microscope. Each sample was incubated with whole saliva or phosphate-buffered saline for 2 hours. Measurements of CHX release were performed using spectrometry on days 1, 2, and 5 after 1-minute exposure to 0.5% chlorhexidine digluconate solution during a 5-day cycle. CHX-releasing experiments were repeated three consecutive times for 15 days. The antimicrobial activity of CHX-adsorbed disks was determined by a disk diffusion test using Streptococcus gordonii.
  
  
  RESULTS
  The CHX-adsorbed titanium surfaces exhibited a short-term release of CHX, and CHX levels dropped rapidly within 3 days. SLA and RBM with smaller and narrower depressions released more CHX than HNF and MA, specifically in the saliva-coated group. The disk diffusion test revealed that after CHX uptake, saliva-coated SLA and RBM showed the highest antimicrobial activity.
  
  
  CONCLUSIONS
  This study suggests that CHX release is significantly influenced by titanium surface modifications and that SLA and RBM might provide effective CHX uptake capacity in the saliva-filled oral cavity.
authors.affiliation: Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Korea.|Dental Research Institute, School of Dentistry, Seoul National University.
authors.forename: Hyo-Sook
authors.initials: HS
authors.lastname: Ryu
authors.affiliation: Dental Research Institute, School of Dentistry, Seoul National University.|Department of Orthodontics, School of Dentistry, Seoul National University.
authors.forename: Yoon-Il
authors.initials: YI
authors.lastname: Kim
authors.affiliation: Dental Research Institute, School of Dentistry, Seoul National University.|Department of Dental Biomaterials, School of Dentistry, Seoul National University.
authors.forename: Bum-Soon
authors.initials: BS
authors.lastname: Lim
authors.affiliation: Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Korea.|Dental Research Institute, School of Dentistry, Seoul National University.
authors.forename: Young-Jun
authors.initials: YJ
authors.lastname: Lim
authors.affiliation: Dental Research Institute, School of Dentistry, Seoul National University.|Department of Orthodontics, School of Dentistry, Seoul National University.
authors.forename: Sug-Joon
authors.initials: SJ
authors.lastname: Ahn
mesh_terms: D000890:Anti-Infective Agents / Q000493:pharmacokinetics*; D000891:Anti-Infective Agents, Local; D002710:Chlorhexidine / Q000493:pharmacokinetics*; D015921:Dental Implants; D057873:Peri-Implantitis; D013499:Surface Properties; D014025:Titanium
chemical_list: D000890:Anti-Infective Agents; D000891:Anti-Infective Agents, Local; D015921:Dental Implants; D014025:Titanium; D002710:Chlorhexidine
keywords: Antimicrobial agents; chlorhexidine; dental implants; dental plaque; microbiology; titanium