title: Calcium sulphate as a bone substitute for various osseous defects in conjunction with apicectomy.
abstract: OBJECTIVE
  The purpose of this study was to investigate the effect of calcium sulphate on various osseous defects when used in conjunction with apicectomy.
  
  
  METHODS
  Mandibular third and fourth premolars of 11 beagle dogs were used. After root-canal treatment and apicectomy, three types of osseous defects were prepared on both sides of the mandible as follows: type 1, osseous defect communicating with the gingival sulcus: type 2, large osseous defect including two roots; type 3, 'through and through' osseous defect. The experimental side was allocated randomly, and the osseous defects were filled with medical grade calcium sulphate. The defects on the opposite side were left unfilled as controls. The dogs were sacrificed at 8 and 16 weeks postoperatively. Undemineralized sections were obtained and examined histomorphometrically.
  
  
  RESULTS
  In type 1 defects, bone was not observed on the buccal side of the root on either experimental or control side at 8 and 16 weeks. In both type 2 and 3 defects, bone volume/tissue volume (BV/TV) values on the experimental side were significantly higher than those on the control side (P < 0.01), and mineral apposition rate (MAR) values on the experimental side were significantly higher than those on the control side (P < 0.01).
  
  
  CONCLUSIONS
  The use of calcium sulphate was effective in bone regeneration on both large osseous defects and 'through and through' osseous defects. It was less effective in osseous defects communicating with the gingival sulcus.
authors.affiliation: Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, 5-45 Yushima 1-chome, Bunkyo-ku, Tokyo 113-8549, Japan. y.murashima.endo@tmd.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Murashima
authors.forename: G
authors.initials: G
authors.lastname: Yoshikawa
authors.forename: R
authors.initials: R
authors.lastname: Wadachi
authors.forename: N
authors.initials: N
authors.lastname: Sawada
authors.forename: H
authors.initials: H
authors.lastname: Suda
mesh_terms: D016301:Alveolar Bone Loss / Q000601:surgery; D000704:Analysis of Variance; D000818:Animals; D001047:Apicoectomy; D001641:Bicuspid / Q000601:surgery; D015519:Bone Density; D001861:Bone Regeneration; D018786:Bone Substitutes / Q000627:therapeutic use*; D002133:Calcium Sulfate / Q000627:therapeutic use*; D004285:Dogs; D005456:Fluorescent Dyes; D017823:Furcation Defects / Q000601:surgery; D008336:Mandibular Diseases / Q000601:surgery*; D010012:Osteogenesis; D011897:Random Allocation; D012390:Root Canal Therapy; D013997:Time Factors
chemical_list: D018786:Bone Substitutes; D005456:Fluorescent Dyes; D002133:Calcium Sulfate