title: The use of guided tissue regeneration principles in endodontic surgery for induced chronic periodontic-endodontic lesions: a clinical, radiographic, and histologic evaluation.
abstract: BACKGROUND
  Chronic periodontic-endodontic lesions are not uncommon in clinical practice and their regenerative capacity has long been questioned. However, there are no published studies investigating the application of guided tissue regeneration techniques in combination with endodontic surgery using an induced perio-endo defect model. This study evaluated the clinical, radiographic, and histologic outcomes of three surgical procedures used to treat induced perio-endo lesions.
  
  
  METHODS
  Pulpal necrosis was induced in foxhounds along with surgical removal of radicular buccal bone. After 4 weeks, chronic lesions were clinically and radiographically assessed. Treatment surgery consisted of apicoectomy, root canal instrumentation, and retrofilling with mineral trioxide aggregate. Teeth were then assigned to one of the following treatment groups: open flap debridement only (OFD), OFD with bioabsorbable porcine-derived collagen membrane (BG), or OFD with BG and anorganic bovine bone matrix (BO/BG). Clinical parameters and standardized radiographs were assessed at defect creation; treatment surgery; and at 1, 2, 4, and 6 months. Animals were sacrificed at 6 months and specimens prepared for histometric analysis.
  
  
  RESULTS
  Clinical and radiographic conditions improved during the study period. Mean epithelial attachment was similar between all groups. Mean connective tissue attachment for groups OFD, BG, and BO/BG was 3.79 mm, 2.63 mm, and 1.75 mm, respectively, and mean radicular bone height was 2.16 mm, 3.24 mm, and 3.45 mm, respectively. Statistically significant increases in the amount of new cementum were observed in groups BG and BO/BG when compared with OFD (P <0.05).
  
  
  CONCLUSIONS
  Treatment of combined induced perio-endo lesions using bioabsorbable collagen membranes alone or in combination with anorganic bovine bone matrix resulted in increased amounts of bone, periodontal ligament, and significant increases in the amount of new cementum when compared to open flap debridement in a canine model.
authors.affiliation: Private practice, Fort Worth, TX, USA.
authors.forename: Steven K
authors.initials: SK
authors.lastname: Britain
authors.forename: Thomas von
authors.initials: Tv
authors.lastname: Arx
authors.forename: Robert K
authors.initials: RK
authors.lastname: Schenk
authors.forename: Daniel
authors.initials: D
authors.lastname: Buser
authors.forename: Pirkka
authors.initials: P
authors.lastname: Nummikoski
authors.forename: David L
authors.initials: DL
authors.lastname: Cochran
mesh_terms: D020341:Absorbable Implants; D017607:Aluminum Compounds / Q000627:therapeutic use; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D000539:Alveolar Process / Q000000981:diagnostic imaging / Q000473:pathology; D000818:Animals; D001047:Apicoectomy; D001857:Bone Matrix / Q000637:transplantation; D017610:Calcium Compounds / Q000627:therapeutic use; D003094:Collagen; D003739:Dental Cementum / Q000473:pathology; D003790:Dental Pulp Necrosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D004195:Disease Models, Animal; D004285:Dogs; D004338:Drug Combinations; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods*; D008567:Membranes, Artificial; D010087:Oxides / Q000627:therapeutic use; D017622:Periodontal Attachment Loss / Q000601:surgery; D010865:Pilot Projects; D011859:Radiography; D012184:Retrograde Obturation; D012387:Root Canal Filling Materials / Q000627:therapeutic use; D018915:Root Canal Preparation; D012390:Root Canal Therapy / Q000379:methods*; D017640:Silicates / Q000627:therapeutic use; D013524:Surgical Flaps; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D008567:Membranes, Artificial; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; D003094:Collagen