title: Sequential healing at implants installed immediately into extraction sockets. An experimental study in dogs.
abstract: OBJECTIVE
  To compare the sequential healing at implants installed in a healed alveolar bony ridge or immediately after tooth extraction without functional load.
  
  
  METHODS
  In the mandible of 12 dogs, the mesial roots of the first molars were endodontically treated, the tooth hemisected, and the distal roots extracted. After 3 months, the mesial roots of the fourth premolars were endodontically treated, the tooth hemisected, and the distal roots extracted in one side of the mandible. Implants were placed immediately into extraction sockets (IPIES) of the fourth premolar and in the healed sites in the molar regions. Healing abutments were placed, and the flaps were sutured to allow a non-submerged healing. The time of surgery and of sacrifices were planned in such a way to obtain biopsies representing the healing after 1 and 2 weeks and 1 and 3 months, respectively. Ground sections were prepared for histological evaluation of tissues components on the implant surface and the coronal termination level of osseointegration (M-B).
  
  
  RESULTS
  New bone apposition on the implant surface was slightly higher at the healed compared to the IPIES sites, being 7.4% and 4.1% after 1 week, and 67.3% and 65.3% after 3 months, respectively. Old bone was progressively resorbed, from 27.0% and 21.9% after 1 week, to 2.5% and 2.0% after 3 months, at healed and IPIES sites, respectively. M-B was 1.4 mm and 2.6 mm after 1 week, 1.2 mm and 1.2 mm after 3 months, at healed and IPIES sites, respectively.
  
  
  CONCLUSIONS
  Similar patterns of sequential osseointegration were found at implants installed in healed alveolar bone or in alveolar sockets immediately after tooth extraction. The coronal termination level of osseointegration, that was different after 1 week, was found similar at the 3-month observation.
authors.affiliation: Faculty of Dentistry, University of Medical Science, La Habana, Cuba.
authors.forename: Tomaso
authors.initials: T
authors.lastname: Mainetti
authors.affiliation: Center for Dental Medicine, University of Zurich, Zurich, Switzerland.|University of Bern, Bern, Switzerland.
authors.forename: Niklaus P
authors.initials: NP
authors.lastname: Lang
authors.affiliation: Faculty of Dentistry, University of Medical Science, La Habana, Cuba.
authors.forename: Franco
authors.initials: F
authors.lastname: Bengazi
authors.affiliation: Faculty of Dentistry, University of Medical Science, La Habana, Cuba.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Favero
authors.affiliation: Faculty of Dentistry, University of Medical Science, La Habana, Cuba.
authors.forename: Luis
authors.initials: L
authors.lastname: Soto Cantero
authors.affiliation: Faculty of Dentistry, University of Medical Science, La Habana, Cuba.|ARDEC, Ariminum Odontologica, Rimini, Italy.|UNESP - Faculdade de Odontologia de Araçatuba, UNESP - Universidade Estadual Paulista, São Paulo, Brasil.
authors.forename: Daniele
authors.initials: D
authors.lastname: Botticelli
mesh_terms: D000818:Animals; D001641:Bicuspid / Q000601:surgery; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D004285:Dogs; D057893:Immediate Dental Implant Loading; D008334:Mandible / Q000601:surgery; D008963:Molar / Q000601:surgery; D016348:Osseointegration / Q000502:physiology*; D013524:Surgical Flaps; D014081:Tooth Extraction; D020390:Tooth Socket / Q000601:surgery*; D014945:Wound Healing / Q000502:physiology*
chemical_list: D015921:Dental Implants
keywords: animal study; extraction sockets; histology; implants placed immediately into extraction sockets; sequential healing; wound healing