Evaluation of The Stress Distribution on Four Different Peri Implant Bone Types When Loaded with Three Different Implant Lengths Subjected to Vertical and Oblique Forces in the Mandible: A Three-Dimensional Finite Element Analysis

The purpose of this study was to evaluate the stress distribution on four different peri implant bone types when loaded with three different implant lengths subjected to vertical and oblique forces in the mandible. 12 three-dimensional finite element models of the edentulous mandible simulating Type 1, Type 2, Type 3 and Type 4 bone quality according to the classification system of Lekholm and Zarb were created from a computerized tomography image by using the Hypermesh 13.0. Software program, which were loaded with three different implant lengths of 8mm, 11.5mm and 13mm (with titanium abutment and screw retained zirconia crown) modelled in the first molar region. A total force of 300 N was applied in the locations of the central fossa (300 N) in a vertical direction and a total oblique force of 300 N with a 30-degree angle was applied in the locations of the mesiobuccal cusp (150 N) and the distobuccal cusp (150 N) of the first molar. Lesser stresses were created in the peri implant bone by shorter implant lengths in all the four bone types as compared to longer implant lengths when loaded in vertical direction as opposed to on oblique direction.