title: Stress Distribution Around Dental Implants Placed at Different Depths.
abstract: BACKGROUND
  The progressive bone loss at the neck of dental implant is a clinical concern since it affects the maintenance of dental aesthetics. The current study evaluated the influence of insertion depth, prosthetic connection, and type of loading on the stress distribution around dental implants, using photoelastic evaluation.
  
  
  METHODS
  A total of three blocks of photoelastic resin for each type of implant connection (external hexagon, external hexagon flattened, internal hexagon, and Morse taper) were built. Each block differed in the position of the implant platform in relative to the upper margin of the block: I (2 mm below), II (at the same level), and III (2 mm above). A force of 100 N was applied to both straight and tilted abutments. Totally, 4 selected points were evaluated at 1 side of the implant. Quantitative data were collected for the statistical analysis.
  
  
  RESULTS
  A multiple linear regression showed the relation between the stress distribution and the insertion depth. For all the implant types, both with straight and tilted abutments, group I presented the lowest stress concentration around the fixture when compared with group II and III (P < 0.05).
  
  
  CONCLUSIONS
  Within the limitations of this study, it could be concluded that the deeper the insertion, the lower the stress concentration.
authors.affiliation: *Department of Periodontology and Oral Implantology, Dental Research Division, Guarulhos University, Guarulhos †Department of Prosthodontics, School of Dentistry, University of São Paulo, São Paulo, Brazil.
authors.forename: Piero Rocha
authors.initials: PR
authors.lastname: Zanardi
authors.forename: Roberto Chaib
authors.initials: RC
authors.lastname: Stegun
authors.forename: Newton
authors.initials: N
authors.lastname: Sesma
authors.forename: Bruno
authors.initials: B
authors.lastname: Costa
authors.forename: Jamil Awad
authors.initials: JA
authors.lastname: Shibli
authors.forename: Dalva Cruz
authors.initials: DC
authors.lastname: Laganá
mesh_terms: D000539:Alveolar Process / Q000502:physiology*; D001696:Biomechanical Phenomena; D000069343:Bone-Implant Interface / Q000502:physiology; D059605:Dental Implant-Abutment Design; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D006801:Humans; D008422:Materials Testing; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D015921:Dental Implants