title: Histological, radiological and histomorphometric evaluation of immediate vs. non-immediate loading of a zirconia implant with surface treatment in a dog model.
abstract: OBJECTIVE
  The aim of this study was to assess the performance of zirconia implants under immediate loading compared with delayed loading in dogs over 30-90 days.
  
  
  METHODS
  Tooth extractions were made for the subsequent placement of dental implants at premolars P2, P3, P4 and molars M1 bilaterally in the dog mandible. Forty eight zirconia implants, 4 mm in diameter and 10 mm in length, were inserted, whose neck and body surfaces had been treated with femtosecond laser texturing; 24 implants were loaded immediately and 24 remained unloaded during the osseointegration period. Final radiographs were taken recording stability values before sacrifice at 30 or 90 days when sample removal for histological and histomorphometric analysis was performed. Bone-to-implant contact, crestal bone loss and implant stability were evaluated at these two study times.
  
  
  RESULTS
  Bone-to-implant contact values after 30 days were 38.9% for immediately loaded implants and 32% for non-loaded implants. After 90 days, values increased to 65% for immediately loaded and 57.6% for non-loaded implants. After 30 days, there was more crestal bone lost in the non-loaded group (0.58 ± 0.28 mm) compared with the immediately loaded group (0.5 ± 0.3 mm). After 90 days, there was improved stability in both groups, but was lower in the immediately loaded group (0.5 ± 0.23 mm) compared with the non-loaded group (0.56 ± 0.28 mm). Initial implant stability values were -3.5 PTV at the moment of implant placement. Stability values after the first 30 days were -4 for immediately loaded implants and -3 for non-loaded. At 90 days, non-loaded implants showed -4.9, whereas immediately loaded showed -7.1.
  
  
  CONCLUSIONS
  For the different parameters studied, zirconia implants treated with femtosecond laser and subjected to immediate loading showed better results compared with non-loaded implants in terms of BIC, crestal bone loss and implant stability.
authors.affiliation: Department of Implant Dentistry, Faculty of Medicine and Dentistry, University of Murcia, Murcia, Spain.
authors.forename: Jose L
authors.initials: JL
authors.lastname: Calvo-Guirado
authors.forename: Antonio
authors.initials: A
authors.lastname: Aguilar-Salvatierra
authors.forename: Gerardo
authors.initials: G
authors.lastname: Gomez-Moreno
authors.forename: Javier
authors.initials: J
authors.lastname: Guardia
authors.forename: Rafael A
authors.initials: RA
authors.lastname: Delgado-Ruiz
authors.forename: Jose Eduardo
authors.initials: JE
authors.lastname: Mate-Sanchez de Val
mesh_terms: D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000473:pathology*; D000818:Animals; D001862:Bone Resorption / Q000473:pathology; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D004285:Dogs; D057893:Immediate Dental Implant Loading / Q000379:methods; D007834:Lasers; D008297:Male; D008334:Mandible / Q000601:surgery; D023421:Models, Animal; D016348:Osseointegration / Q000502:physiology; D011859:Radiography; D013499:Surface Properties; D014081:Tooth Extraction; D015040:Zirconium
chemical_list: D015921:Dental Implants; D015040:Zirconium; C028541:zirconium oxide
keywords: BIC; Zirconia implants; crestal bone loss; immediate loading; implant stability