Finite element analysis on screw type implant in the type IV regenerated bone

ABSTRACT

bone quality on the transmission of occlusal forces for endosseous dental implants. Using the finite element method, the study modeled 4.1- * 11.5-mm threaded implant (3i, USA) placed in a 20 mm in height and 10 mm in diameter, was assumed to be 100% osseointegrated. Using ANSYS software revision 6.0, a program was written to generate a model simulating a cylindrical block section of the mandible 20 mm in height and 10 mm in diameter. The regenerated bone (bone quality type IV bone), with 4 mm in width, was made from the platform of implant to 7 mm apical along the side of implant A load of 200N was applied at the 3 occlusal surfaces of the restoration, the central fossa (A), outsidepoint of the central fossa with resin filling into screw hole (B), and the buccal cusp (C), at a 0 degree and a 30 degrees angle to the vertical axis of the implant, respectively. The present study used a fine grid model incorporating elements between 250,820 and 352,494 and nodal points between 47,978 and 67,471. The stress values on regenerated bone-implant interface were influenced by both native bone adjacent to regenerated bone and loading type on the occlusal surface in the implant. It was found that stresses were more homogeneously distributed along the side of implant when more spongy bone was present, regardless of load direction. The higher stresses were generated at the 1 mm and 3 mm bone-implant interface below marginal bone. In summary, our investigation indicates choosing the adequate surgical therapy for the implant to be placed into bone with the good quality and the adequate occlusal rehabilitation according to bone quality adjacent to implant fixture need in making a treatment planning for implant supported prosthesis.