title: Influence of autogenous platelet concentrate on combined GTR/graft therapy in intrabony defects: a 7-year follow-up of a randomized prospective clinical split-mouth study.
abstract: OBJECTIVE
  To investigate the influence of autogenous platelet concentrate (APC) on the long-term regeneration outcome 7 years after guided tissue regeneration (GTR) in deep intrabony periodontal defects.
  
  
  METHODS
  In 25 patients, two deep contra-lateral intrabony defects were treated according to GTR (randomized split-mouth-design). In the test defects, APC was additionally applied. After 7 years, healing results were assessed clinically by a blinded examiner and compared to baseline and 12-months results. Furthermore, a tooth survival analysis was performed.
  
  
  RESULTS
  After 7 years, 23 patients were available for survival analysis and 16 patients for split-mouth analysis; 84% of the test and control teeth were still in situ. In both groups, the median attachment level of 10.5 mm [(25/75%): test 9.0/13.0, control 10.0/12.0] at baseline was significantly (p ≤ 0.05) reduced to 6.0 mm [test 4.0/6.8, control 5.0/7.0] after 1 year. Six years later, it had increased again to 7.0 mm in test sites [5.3/10.0] (p ≤ 0.05) and had remained stable in control sites [5.0/7.8] (p > 0.05). Bleeding on Probing (BOP) had increased in both groups. During the last 6 years, only 26% of the patients received a structured supportive periodontal therapy in the clinic.
  
  
  CONCLUSIONS
  Within its limitations, the present study indicates that the clinical outcome of GTR therapy can be maintained over 7 years. However, the additional use of APC may even have a possibly negative influence on the long-term stability.
authors.affiliation: Department of Operative Dentistry and Periodontology, University of Regensburg, Regensburg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Moder
authors.forename: Frederike
authors.initials: F
authors.lastname: Taubenhansl
authors.forename: Karl-Anton
authors.initials: KA
authors.lastname: Hiller
authors.forename: Gottfried
authors.initials: G
authors.lastname: Schmalz
authors.forename: Michael
authors.initials: M
authors.lastname: Christgau
mesh_terms: D016301:Alveolar Bone Loss / Q000145:classification / Q000601:surgery*; D001804:Blood Transfusion, Autologous; D016025:Bone Transplantation / Q000379:methods*; D003774:Dental Plaque Index; D005500:Follow-Up Studies; D005889:Gingival Recession / Q000145:classification; D005891:Gingivitis / Q000145:classification; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods*; D006801:Humans; D008137:Longitudinal Studies; D010349:Patient Compliance; D017622:Periodontal Attachment Loss / Q000145:classification / Q000601:surgery; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000145:classification / Q000601:surgery; D017713:Platelet Transfusion; D011446:Prospective Studies; D014081:Tooth Extraction; D016388:Tooth Loss / Q000145:classification; D016896:Treatment Outcome