title: Evaluation of Guided Bone Regeneration around Oral Implants over Different Healing Times Using Two Different Bovine Bone Materials: A Randomized, Controlled Clinical and Histological Investigation.
abstract: OBJECTIVE
  To evaluate the potential of two bone substitute materials and the influence of different healing periods in guided bone regeneration therapy of osseous defects around implants.
  
  
  METHODS
  Twenty-four edentulous patients received implants in the region of the lost lower incisors. Around two standardized osseous defects were created, treated either with a 50:50 mixture of PepGen P-15® and OsteoGraf®/N-700 (test group) or with BioOss® (control group), and covered with titanium membranes. After healing periods of 2, 4, 6, or 9 months, the implants were removed together with the surrounding bone and subsequently prepared for histological evaluations.
  
  
  RESULTS
  Defect depths in both groups showed a clinical reduction after intervention. The histologically measured distance from the implant shoulder to the first point of bone-implant contact (BIC) after treatment did not differ between the two groups. The healing time influenced the level of the first point of BIC, with a longer healing period producing a more coronal first point of BIC. A greater percentage BIC and a higher fraction of mineralized bone were found in the pristine bone area compared with the augmented defect area.
  
  
  CONCLUSIONS
  It can be concluded that in the treatment of osseous defects around oral implants, both materials were equally effective bone substitute materials when used in combination with guided bone regeneration.
authors.affiliation: Department of Prosthodontics, School of Dentistry, University Medical Center, Freiburg, Germany.
authors.forename: Ralf Joachim
authors.initials: RJ
authors.lastname: Kohal
authors.affiliation: Chung-U Nam Dental Practice, Berlin, Germany.
authors.forename: Lisa Marie
authors.initials: LM
authors.lastname: Straub
authors.affiliation: Institute of Medical Biometry and Medical Informatics, University of Freiburg, Freiburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Wolkewitz
authors.affiliation: Department of Prosthodontics, School of Dentistry, University Medical Center, Freiburg, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Bächle
authors.affiliation: Department of Prosthodontics, School of Dentistry, University Medical Center, Freiburg, Germany.|Department of Periodontics, School of Dentistry, University of Maryland, Baltimore, MD, USA.
authors.forename: Sebastian Berthold Maximilian
authors.initials: SB
authors.lastname: Patzelt
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001861:Bone Regeneration; D018786:Bone Substitutes / Q000494:pharmacology*; D002417:Cattle; D015921:Dental Implants; D005260:Female; D006801:Humans; D007575:Jaw, Edentulous / Q000601:surgery*; D008297:Male; D008334:Mandible / Q000601:surgery*; D008875:Middle Aged; D013997:Time Factors; D014945:Wound Healing / Q000187:drug effects
chemical_list: D018786:Bone Substitutes; D015921:Dental Implants; C118792:OsteoGraf-N; C403137:PepGen P-15
keywords: bone regeneration; bone substitute; dental materials; histology; microscopy; oral implants