title: Effect of Induced Periimplantitis on Dental Implants With and Without Ultrathin Hydroxyapatite Coating.
abstract: OBJECTIVE
  The aim of this study was to compare the effect of ligature-induced periimplantitis on dental implants with and without hydroxyapatite (HA) coat.
  
  
  METHODS
  Thirty-two dental implants (3.3 mm wide, 13 mm long) with 4 surface treatments (8 implant/group) (M: machined, SA: sandblasted acid etched, S: sputter HA coat and P: plasma-sprayed HA coat) were inserted into canine mandibles. After 12 weeks, oral hygiene procedures were stopped and silk ligatures were placed around the implant abutments to allow plaque accumulation for the following 16 weeks. Implants with the surrounding tissues were retrieved and prepared for histological examination. Bone-to-implant contact (BIC) and implant surfaces were examined using scanning electron microscopy and energy dispersive x-ray spectroscopy.
  
  
  RESULTS
  Histological observation revealed marginal bone loss and large inflammatory cell infiltrates in the periimplant soft tissue. Sputter HA implants showed the largest BIC (98.1%) and machined implant showed the smallest values (70.4%). After 28 weeks, thin sputter HA coat was almost completely dissolved, whereas plasma-sprayed HA coat showed complete thickness preservation.
  
  
  CONCLUSIONS
  Thin sputter HA-coated implants showed more bone implant contact and less marginal bone loss than thick HA-coated implants under periimplantitis condition.
authors.affiliation: *Lecturer, Department of Oral Medicine, Periodontology, Diagnosis and Radiology, Faculty of Dentistry, Alexandria University, Alexandria, Egypt. †Lecturer, Department of Oral Surgery, Faculty of Dentistry, Pharos University, Alexandria, Egypt. ‡Professor, Research Center for Medical and Dental Science, Tokyo Medical and Dental University, Tokyo, Japan. §Professor and Head of Department, Oral Implantology and Regenerative Dental Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Marwa
authors.initials: M
authors.lastname: Madi
authors.forename: Osama
authors.initials: O
authors.lastname: Zakaria
authors.forename: Shizuko
authors.initials: S
authors.lastname: Ichinose
authors.forename: Shohei
authors.initials: S
authors.lastname: Kasugai
mesh_terms: D000818:Animals; D003757:Dental Implantation / Q000379:methods*; D015921:Dental Implants; D004285:Dogs; D017886:Durapatite / Q000008:administration & dosage / Q000627:therapeutic use*; D008855:Microscopy, Electron, Scanning; D057873:Peri-Implantitis / Q000150:complications* / Q000473:pathology; D013052:Spectrometry, X-Ray Emission
chemical_list: D015921:Dental Implants; D017886:Durapatite