title: Impact of Dynamic and Static Load on Bone Around Implants: An Experimental Study in a Rat Model.
abstract: OBJECTIVE
  This study aimed to evaluate peri-implant bone reactions to dynamic and static loads in a rat model.
  
  
  METHODS
  Two cylindrical titanium implants were placed in the left tibia diaphysis of 39 rats, which were divided into three groups: static load for 4 weeks (S4), static load for 8 weeks (S8), and static load for 4 weeks followed by dynamic load for 4 weeks (S4D4). All implants received a mechanical lateral load. After the experiment, the implants were extracted to determine the attachment strength around the bone and implant. The new bone formation and bone-to-implant contact were measured using plain and polarized light microscopy.
  
  
  RESULTS
  Histologic tissue analysis revealed good contact between the bone and implant, and new bone formation around all implants. The S4D4 group had the greatest attachment strength, new bone formation, and complex collagen fiber orientation in the new bone tissue, compared with the other groups. No statistically significant differences in bone-to-implant contact were observed among the three groups.
  
  
  CONCLUSIONS
  Applying dynamic and static loads to osseointegrated implants increased the amplification of new bone. The attachment strength was significantly improved when dynamic load was used for 4 weeks, compared with when static load was used.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yagihara
authors.forename: Ryo
authors.initials: R
authors.lastname: Kawasaki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mita
authors.forename: Kazuo
authors.initials: K
authors.lastname: Takakuda
mesh_terms: D000818:Animals; D000069343:Bone-Implant Interface / Q000502:physiology*; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D004195:Disease Models, Animal; D020007:Implants, Experimental; D016348:Osseointegration / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013314:Stress, Mechanical; D013977:Tibia / Q000601:surgery; D014025:Titanium; D016474:Weight-Bearing / Q000502:physiology*
chemical_list: D015921:Dental Implants; D014025:Titanium