title: Ultraviolet-C irradiation to titanium implants increases peri-implant bone formation without impeding mineralization in a rabbit femur model.
abstract: OBJECTIVE
  Volume and bone quality of peri-implant supporting bone, in particular, at implant neck region, as well as bone-implant contact ratio, is important for long-term stability of implants. Ultraviolet-C (UVC) irradiation is known to enhance the osseointegration capability of titanium implants. However, the histological determination was performed only on a rat model, but not pre-clinical animal model such as a rabbit model. The purpose of this study was to determine the effects of UVC irradiation on titanium implants on the volume and mineral density of peri-implant supporting bone formation in a rabbit femur model.
  
  
  METHODS
  Acid-etched pure titanium screw implants with or without 3 mW/cm2 UVC irradiation for 48 h were placed in rabbit femur diaphyses. Peri-implant bone tissue formation was analyzed at 3 and 8 weeks post-operatively by histology and micro-CT-based bone morphometry after calibration with hydroxyl apatite phantoms.
  
  
  RESULTS
  UVC pre-irradiated implants accumulated a higher density of cells and thicker and longer bone tissue attachments that continued into the inner basic lamellae of the surface of existing cortical bone at 3 and 8 weeks than the implants without irradiation. Although the bone mineral density around both implants was equivalent to that of the existing cortical bone, bone volume was greater with UVC pre-irradiation in two-thirds or more of the apical region throughout the observation period.
  
  
  CONCLUSIONS
  These results indicate that UVC treatment increased the volume of cortical-like bone tissue in the coronal region of titanium implants without deterioration of bone mineral density.
authors: Department of Removable Prosthodontics and Gerodontology.
authors: Makoto
authors: M
authors: Yamazaki
authors: Masahiro
authors: M
authors: Yamada
authors: Ken
authors: K
authors: Ishizaki
authors: Kaoru
authors: K
authors: Sakurai
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000818:Animals; D015519:Bone Density / Q000502:physiology; D000069343:Bone-Implant Interface / Q000502:physiology; D002113:Calcification, Physiologic / Q000502:physiology*; D002448:Cell Adhesion / Q000502:physiology; D002452:Cell Count; D015921:Dental Implants; D003764:Dental Materials / Q000528:radiation effects*; D017267:Dental Prosthesis Design; D005269:Femur / Q000473:pathology / Q000601:surgery; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D023421:Models, Animal; D016348:Osseointegration / Q000502:physiology; D010012:Osteogenesis / Q000502:physiology*; D011817:Rabbits; D013464:Sulfuric Acids / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium / Q000528:radiation effects*; D014466:Ultraviolet Rays / Q000145:classification; D017155:Wettability; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: D015921:Dental Implants; D003764:Dental Materials; D013464:Sulfuric Acids; D014025:Titanium; C033158:sulfuric acid
keywords: contact osteogenesis; microCT; osseointegration; photo-functionalization; surface modification