title: Assessment of Intraobserver and Interobserver Agreement of a New Classification System for Retrograde Periimplantitis.
abstract: BACKGROUND
  Retrograde periimplantitis (RPI) is the inflammatory disease that affects the apical part of an osseointegrated implant while the coronal portion of the implant sustains a normal bone-to-implant interface. The aim of the current study was to assess the intraexaminer and interexaminer reliability of a proposed new classification system for RPI.
  
  
  METHODS
  After thorough electronic literature search, 56 intraoral periapical radiographs (IOPA) of implants with RPI were collected and were classified by 2 independent reviewers as per the new classification system into one of the 3-mild, moderate, and advanced-classes based on the amount of bone loss from the apex of the implant to the most coronal part as a percentage of the total implant length. The IOPAs were assessed twice by the same examiners and both were blinded to each other's observations.
  
  
  RESULTS
  The intraobserver agreement ranged from 0.85 to 0.91, which falls under the category of almost perfect agreement. The interexaminer agreement was found to be 0.83, also considered as almost perfect agreement.
  
  
  CONCLUSIONS
  The proposed classification shows good intraexaminer and interexaminer reliability and can be used for treatment planning and prognosis in cases of RPI.
authors.affiliation: *Lecturer, Department of Periodontics, Bapuji Dental College and Hospital, Davangere, India. †Professor, Department of Periodontics, Bapuji Dental College and Hospital, Davangere, India. ‡Professor & Head, Department of Periodontics, Bapuji Dental College and Hospital, Davangere, India.
authors.forename: Rucha
authors.initials: R
authors.lastname: Shah
authors.forename: Raison
authors.initials: R
authors.lastname: Thomas
authors.forename: Tarun
authors.initials: T
authors.lastname: Kumar
authors.forename: Dhoom Singh
authors.initials: DS
authors.lastname: Mehta
mesh_terms: D003757:Dental Implantation / Q000009:adverse effects; D006801:Humans; D015588:Observer Variation; D057873:Peri-Implantitis / Q000145:classification* / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology; D010519:Periodontium / Q000473:pathology; D011861:Radiography, Dental