title: Endodontic treatment of teeth induces retrograde peri-implantitis.
abstract: OBJECTIVE
  Some cases of retrograde peri-implantitis arise from adjacent natural teeth that have peri-radicular infection. The present study was designed to investigate the incidence of retrograde peri-implantitis from adjacent teeth with endodontic treatment.
  
  
  METHODS
  One hundred and twenty-eight patients of ages ranging from of 24-61 years were recruited for this study. A total of 128 ITI SLA implants with adjacent teeth that had received endodontic treatment at least 1 week before were placed in 128 patients. The date of endodontic therapy and the pulp status of the adjacent tooth before endodontic therapy were recorded. The distance between the implant and the adjacent tooth was determined using a radiograph. The stability of all implants was tested by OSSTELL and recorded at implant placement, after 4 and 12 weeks.
  
  
  RESULTS
  The incidence of retrograde peri-implantitis was 7.8%. The duration from endodontic-treated adjacent teeth to implant placement was 12.15+/-10.1 weeks, and the distance between the implant and the adjacent teeth was 2.99+/-1.4 mm. Distance and time were found to be related to retrograde peri-implantitis (P<0.05). The stability of implants with retrograde peri-implantitis was less than that of the normal implants, but the difference was not significant (P>0.05).
  
  
  CONCLUSIONS
  The incidence of retrograde peri-implantitis may reduce by increasing the distance between the implant and adjacent tooth, and/or the duration from endodontically treated adjacent tooth-to-implant placement. Although preliminary, these data might orient the practitioner to avoid retrograde peri-implantitis.
authors.affiliation: Department of Implant Dentistry, School of Stomatology, Fourth Military Medical University, Xi'an, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.forename: Chun
authors.initials: C
authors.lastname: Han
authors.forename: Dehua
authors.initials: D
authors.lastname: Li
authors.forename: Yunming
authors.initials: Y
authors.lastname: Li
authors.forename: Yingliang
authors.initials: Y
authors.lastname: Song
authors.forename: Yimin
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015921:Dental Implants / Q000009:adverse effects*; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010485:Periapical Periodontitis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology*; D011857:Radiographic Image Interpretation, Computer-Assisted; D012307:Risk Factors; D012390:Root Canal Therapy / Q000009:adverse effects*
chemical_list: D015921:Dental Implants