title: A clinical and histological report of a tooth with an open apex treated with regenerative endodontics using platelet-rich plasma.
abstract: BACKGROUND
  In patients, the outcomes of teeth with necrotic pulps and open apexes that have been treated with regenerative endodontics have always been evaluated clinically and radiographically. The purpose of this case report is to present the clinical, radiographic, and histological findings of a regenerative procedure using platelet-rich plasma (PRP) 14 months after the procedure.
  
  
  METHODS
  A 12-year-old boy whose maxillary second premolar tooth had been treated with regenerative endodontics was seen with a chief complaint of pain and sensitivity to cold. After clinical and radiographic examinations, a pulpal diagnosis of reversible pulpitis and normal periapical tissues was made for this tooth. Because of the patient's complaint and his guardian's insistence on either a root canal treatment or an extraction, a root canal treatment was performed in this tooth. After entry into the root canal, the soft tissue present in the canal was removed with the aid of a large barbed broach and examined histologically.
  
  
  RESULTS
  Examination of the tissue removed from the root canal of this tooth revealed the presence of a vital pulp-like vital connective tissue. There was no evidence of bone in the specimen. Very few inflammatory cells were noted in the periphery of the specimen.
  
  
  CONCLUSIONS
  Based on these findings, it appears that pulp-like tissue can be generated in a human tooth with the use of PRP as a scaffold in regenerative endodontic procedures.
authors.affiliation: Department of Endodontics, School of Dentistry, Londa Linda University, Loma Linda, California 92350, USA. mtorabinejad@llu.edu
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Torabinejad
authors.forename: Hadi
authors.initials: H
authors.lastname: Faras
mesh_terms: D001641:Bicuspid; D002648:Child; D003782:Dental Pulp / Q000502:physiology*; D003790:Dental Pulp Necrosis / Q000628:therapy*; D006801:Humans; D008297:Male; D008437:Maxilla; D053657:Platelet-Rich Plasma; D012038:Regeneration; D019233:Retreatment; D012390:Root Canal Therapy / Q000379:methods*; D054457:Tissue Scaffolds; D019227:Tooth Apex / Q000254:growth & development*