title: Evaluation of the cylinder implant thread height and width: a 3-dimensional finite element analysis.
abstract: OBJECTIVE
  To evaluate continuous and simultaneous variations of thread height and width for an experimental screw-type implant.
  
  
  METHODS
  A finite element model of an implant with a V-shaped thread was created. The range of thread height was set at 0.20 to 0.60 mm, and the range of thread width was set at 0.10 to 0.40 mm. Forces of 100 N and 50 N were applied along the implant axis (AX) and an angle of 45 degrees in a buccolingual direction (45-degree BL), respectively. The maximum von Mises stresses in jawbone were evaluated, and the sensitivity of the stress in jawbone to the variables was also evaluated.
  
  
  RESULTS
  Under AX load, the maximum von Mises stresses in cortical and cancellous bones increased by 4.3% and 63.0%, respectively, as thread parameters changed. Under 45-degree BL load, maximum von Mises stresses in cortical and cancellous bones increased by 19.3% and 118.0%, respectively. When thread height was from 0.34 to 0.50 mm and thread width was 0.18 to 0.30 mm, the tangent slope of the maximum von Mises stress response curve ranged from -1 to 1. The variation of the maximum von Mises stresses in jawbone was more sensitive to thread height than to thread width.
  
  
  CONCLUSIONS
  Stress in cancellous bone is more likely to be influenced by thread parameters than stress in cortical bone. A 45-degree BL force is more likely to be influenced by thread parameters than an axial force. A thread height of 0.34 to 0.50 mm and a thread width of 0.18 to 0.30 mm is optimal from a biomechanical point of view. In the design of a screw-type implant, thread height is more important than thread width for the reduction of stress within the bone.
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Kong
authors.forename: Kaijin
authors.initials: K
authors.lastname: Hu
authors.forename: Dehua
authors.initials: D
authors.lastname: Li
authors.forename: Yingliang
authors.initials: Y
authors.lastname: Song
authors.forename: Jin
authors.initials: J
authors.lastname: Yang
authors.forename: Ziyan
authors.initials: Z
authors.lastname: Wu
authors.forename: Baolin
authors.initials: B
authors.lastname: Liu
mesh_terms: D000539:Alveolar Process / Q000502:physiology / Q000601:surgery; D001696:Biomechanical Phenomena; D001863:Bone Screws; D003198:Computer Simulation; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D003799:Dental Stress Analysis / Q000379:methods*; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional; D016348:Osseointegration / Q000502:physiology; D013314:Stress, Mechanical
chemical_list: D015921:Dental Implants