title: Healing of buccal dehiscence defects at implants installed immediately into extraction sockets - an experimental study in dogs.
abstract: OBJECTIVE
  To evaluate the influence of implant positioning into extraction sockets on bone formation at buccal alveolar dehiscence defects.
  
  
  METHODS
  In six Labrador dogs the pulp tissue of the mesial roots of (4) P(4)  was removed and the root canals were filled. Flaps were elevated bilaterally, the premolars hemi-sectioned and the distal roots removed. The implants were placed in contact with either the buccal (test site) or with the lingual (control site) bony wall of the extraction sockets. Healing abutments were affixed and triangular buccal bony dehiscence defects, about 2.7 mm deep and 3.5 mm wide, were then prepared. No regenerative procedures were done and a non-submerged healing was allowed. After 4 months of healing, block sections of the implant sites were obtained for histological processing and peri-implant tissue assessment.
  
  
  RESULTS
  After 4 months of healing, the bony crest and the coronal border of osseointegration at the test sites were located 1.71 ± 1.20 and 2.50 ± 1.21 mm apically to the implant shoulder, respectively. At the control sites, the corresponding values were 0.68 ± 0.63 and 1.69 ± 0.99 mm, respectively. The differences between test and control reached statistical significance (P < 0.05). Residual marginal bone defects were found both at the test and control sites. A statistically significant difference between test and control sites was only found at the lingual aspects (depth 2.09 ± 1.01 and 1.01 ± 0.48 mm, respectively). Similar heights of the buccal biological width were observed at both sites (about 5.1 mm).
  
  
  CONCLUSIONS
  The placement of implants in a lingual position of the extraction sockets allowed a higher degree of bone formation at buccal alveolar dehiscence defects compared with a buccal positioning.
authors.affiliation: Faculty of Dentistry, University of Medical Science, La Habana, Cuba.
authors.forename: Eriberto
authors.initials: E
authors.lastname: Bressan
authors.forename: Stefano
authors.initials: S
authors.lastname: Sivolella
authors.forename: Edoardo
authors.initials: E
authors.lastname: Stellini
authors.forename: Zoraya
authors.initials: Z
authors.lastname: Almagro Urrutia
authors.forename: Niklaus Peter
authors.initials: NP
authors.lastname: Lang
authors.forename: Daniele
authors.initials: D
authors.lastname: Botticelli
mesh_terms: D000818:Animals; D000044:Dental Abutments; D015921:Dental Implants; D004285:Dogs; D057893:Immediate Dental Implant Loading; D008334:Mandible / Q000601:surgery*; D016348:Osseointegration; D013524:Surgical Flaps; D013529:Surgical Wound Dehiscence / Q000503:physiopathology*; D014081:Tooth Extraction; D020390:Tooth Socket / Q000601:surgery; D014945:Wound Healing / Q000502:physiology
chemical_list: D015921:Dental Implants