title: High bone-implant contact achieved by photofunctionalization to reduce periimplant stress:  a three-dimensional finite element analysis.
abstract: OBJECTIVE
  A recent study demonstrated that UV treatment of titanium implants (photofunctionalization) enabled a higher level of osseointegration by establishing a 98.2% bone-implant contact (BIC) as opposed to a 53.0% BIC around untreated implants. This study examined whether, and how, the BIC increase affects the periimplant mechanical stress.
  
  
  METHODS
  Three-dimensional finite element analysis was performed on implants of different degrees of BIC (53.0% and 98.2%) based on the report of photofunctionalization. The different lengths of implants (7, 10, and 13 mm) were also tested.
  
  
  RESULTS
  Increasing the implant length from 7 to 13 mm diminished the periimplant stress level by only 15% under vertical load, whereas increasing BIC from 53.0% to 98.2% diminished it by 50%. Consequently, stress around 7-mm implants with 98.2% BIC was even lower than that around 13-mm implants with 53.0% BIC. High-stress areas, which were observed around implants in all lengths with 53.0% BIC, disappeared on implants with 98.2% BIC even on 7-mm implants. Similar results were obtained under oblique load.
  
  
  CONCLUSIONS
  This study demonstrated that a BIC increase from 53.0% to 98.2%, which can be achieved by photofunctionalization, improves distribution and diffusion of periimplant stress more effectively than using longer implants, providing a potential novel strategy to counteract stress-induced periimplant marginal bone loss.
authors: Department of Partial Denture Prosthodontics, Nihon University School of Dentistry, Tokyo, Japan.
authors: Tetsuo
authors: T
authors: Ohyama
authors: Tendo
authors: T
authors: Uchida
authors: Norio
authors: N
authors: Shibuya
authors: Shinya
authors: S
authors: Nakabayashi
authors: Tomohiko
authors: T
authors: Ishigami
authors: Takahiro
authors: T
authors: Ogawa
mesh_terms: D001696:Biomechanical Phenomena; D001842:Bone and Bones / Q000033:anatomy & histology / Q000502:physiology*; D015921:Dental Implants; D003764:Dental Materials / Q000528:radiation effects*; D017267:Dental Prosthesis Design; D055119:Elastic Modulus; D004548:Elasticity; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D016348:Osseointegration / Q000502:physiology*; D013314:Stress, Mechanical; D013499:Surface Properties; D014025:Titanium / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D015921:Dental Implants; D003764:Dental Materials; D014025:Titanium