title: Three dimensional finite element analysis to detect stress distribution in spiral implants and surrounding bone.
abstract: BACKGROUND
  The aim of research was to study spiral family implant by finite element analysis (FEA) inserted in different bone qualities connected with abutments of different angulations.
  
  
  METHODS
  The biomechanical behaviour of 4.2 × 13 mm dental implants, connecting screw, straight and 15° and 25° angulated abutments subjected to static loads, in contact with high and poor bone qualities was evaluated by FEA.
  
  
  RESULTS
  The lowest stress value was found in the system composed by implants and straight abut-ments loaded with a vertical force, while the highest stress value was found in implants with 15° angulated abutment loaded with an angulated force. In addition, we found the lower the bone quality, the higher the distribution of the stress within the bone.
  
  
  CONCLUSIONS
  Spiral family implants can be used successfully in low bone quality but applying a straight force is recommended.
authors.affiliation: Senior Lecturer, School of Dentistry, University of Chieti, Chieti, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Danza
authors.forename: Annalisa
authors.initials: A
authors.lastname: Palmieri
authors.forename: Francesca
authors.initials: F
authors.lastname: Farinella
authors.forename: Giorgio
authors.initials: G
authors.lastname: Brunelli
authors.forename: Francesco
authors.initials: F
authors.lastname: Carinci
authors.forename: Ambra
authors.initials: A
authors.lastname: Girardi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Spinelli