| This study contains two parts, Part I: research on 3-D FEM of the stress of micro-implant - bone interface. Part II: the primary study of homemade micro-implant on animal experiment.First Part:Research on 3-D FEM of the Stress of Micro-implant - Bone Interface[Objective] To build micro-implant-bone model with three-dimensional finite element analyses and find micro-implant of compatible orthodontic clinic[Methods] The finite element model of micro-implant according to the products of DENTOS Company was established with Pro/E and ANSYS. The cross section outline drawn from the maxillary between the second pre-molar and the first molar was input into a computer, and ANSYS was used to perform the finite element modeling of bone. Computer simulates process of micro-implant implanting bone. Micro-implants with different types of strew (triangle and trapezoid) were loaded 100g-400g forces (vertical, horizontal, diagonal) and were Analyzed the stress around them. Their length arranged from 5mm to 10mm respectively. Then, micro-implants with 5mm length were loaded 200g forces (horizontal and diagonal) and were analyzed the stress again when the depths of cortical bone changed (including 1, 1.5, 2.5 and 3.5mm).[Results](l) The stress distributed on the cortical bone when the micro-implants were loaded horizontally and diagonally. But, the stress distributed on the whole bone after vertical load appliance. (2) The von mises stress of triangle strew micro-implant wasn't notable higher than that of trapezoid strew one with same length (except 8mm). (3) Between micro-implants of different length, the von mises stress of 8mm is indistinctively lower than that of the others. However, this rule of stress variety didn't occur when strew of micro-implants was trapezoid. (4) During diagonal force, the thinner the cortical bone around the implant neck, the greater the stress on the bone interface. However, this relation wasn't obvious when micro-implant was forced horizontally.Second PartThe Primary Study of Homemade Micro-implant on Animal Experiment... |
