title: Peri-implant bone reactions at delayed and immediately loaded implants: an experimental study.
abstract: OBJECTIVE
  The aim of this study was to compare the peri-implant bone reactions of implants subjected to immediate loading with those subjected to delayed loading.
  
  
  METHODS
  In 6 mongrel dogs, bilateral edentulated flat alveolar ridges were created in the mandible. After 3 months of healing, 1 implant was placed in each side. On one side of the mandible, the implant was loaded immediately with a force of 20 N that was applied at a 120 degrees angle from the tooth's longitudinal axis at the labial surface of the crown for 1800 cycles per day for 10 weeks. On the opposite side, after a delay of 3 months to allow osseointegration to take place, the implant was loaded with the same force used for the immediately loaded implant. Ten weeks after loading, microscopic computerized tomography at the implantation site was performed. Osseointegration was calculated as the percentage of implant surface in contact with bone. Bone height was measured in the peri-implant bone.
  
  
  RESULTS
  The mean osseointegration was greater (65.5%) for the delayed-loading implants than for the immediately loaded implants (60.9%; P < .05). The mean peri-implant bone height was greater (10.6 mm) for the delayed-loading implants than for the immediately loaded implants (9.6 mm; P < .05).
  
  
  CONCLUSIONS
  The results indicate that when implants are immediately loaded, the immediate loading may decrease both osseointegration of dental implants and bone height.
authors.affiliation: Department of Dentistry, Yonsei University Wonju College of Medicine, Wonju, South Korea.
authors.forename: Se-Hoon
authors.initials: SH
authors.lastname: Kim
authors.forename: Byung-Ho
authors.initials: BH
authors.lastname: Choi
authors.forename: Jingxu
authors.initials: J
authors.lastname: Li
authors.forename: Han-Sung
authors.initials: HS
authors.lastname: Kim
authors.forename: Chang-Yong
authors.initials: CY
authors.lastname: Ko
authors.forename: Seung-Mi
authors.initials: SM
authors.lastname: Jeong
authors.forename: Feng
authors.initials: F
authors.lastname: Xuan
authors.forename: Seoung-Ho
authors.initials: SH
authors.lastname: Lee
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology*; D000818:Animals; D000044:Dental Abutments; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants / Q000009:adverse effects*; D003799:Dental Stress Analysis; D004285:Dogs; D005260:Female; D008334:Mandible; D008409:Mastication; D016348:Osseointegration; D013997:Time Factors
chemical_list: D015921:Dental Implants