Finite Element Analysis Of The Value Of The Maximum Critical Force Suffered In The Immediate Loading Of The Former Dental Implants

Background：Implant denture repair, implant and bone tissue to form a good bonebinding, which requires the implant to avoid stress, control the micro-mobility,dental implant is different from the natural teeth, periodontal tissue. In thisstudy, the anterior teeth implant the size of the micro force do not formresorption. That reasonable fretting should be about100μm micro achieve orimplant and bone will not occur more than150μm, the combination of bone, itwill lead to the peri-implant fibrous capsule, the formation of the fiber binding.Prosthesis force transfer to implant produced by fretting can lead to crestalbone loss, thereby affecting the osseointegration. Fretting over a certainthreshold will affect the osseointegration implant normal move-degreethreshold value of50-150μm micro delivered to the implant body is more than150μm, can interfere with normal peri-implant bone healing. resulting inperi-implant fibrous cysts. Therefore, the micro-mobility of the implant must becontrolled at less than150μm, or else will result in the failure of the implantsurgery.Purpose：Study approached the immediate loading of dental implants, before theformation of bone resorption, to grow the size of the teeth can withstand theforce. Method：The application of Japanese Shimadzu CT scan machine scan of themaxilla, maxillary and implant model using CAD and ANSYS software, theapplication of three-dimensional finite element analysis, analysis andprocessing. The implant angle afterburner, the situation of peri-implant boneremodeling, the establishment of the geometric model of the three-dimensionalfinite element analysis of implant angle load through the computer to calculatethe position and size of the force distribution.On the results of this experiment in the CPU as a Intel Core i5,3200MHz,750G hard disk, memory,4G computer3D-Doctor graphics software and theAltair Hypermesh modeling software to model, solved with ABAQUS analyzersoftware, and post-processing software in the Altair Hyperview calculated andanalyzed.The case of facial appearance is normal, complete dentition, occlusion,alveolar bone loss and periodontal disease, tooth no significant wear of healthyadult male volunteers, pre-made splints, application of Japanese Shimadzucompany CT scan the machine SHMADZUSCT-5000T scan of the maxilla.Maxillary anterior region model, spiral CT on a volunteer adult maleclosed CT scans, the voltage120KV current95mA. Scanning continuouscross-sectional scanning from the occlusal plane to the supraorbital margin ofthe maxillary arch, slice thickness1.2mm, a total of95two-dimensionaltomographic images, the image data stored in DICOM format.Implant model with finite element software to establish a root shapedthread-like implant, implant specifications for head and neck of the cylindrical structure of diameter4.3mm, length of2mm implant a total length of13mm.The upper diameter of4.3mm, the root of the diameter of2mm, the middle wasthe root-shaped curve. Implant thread is0.3mm,0.6mm pitch, angle of90degrees. Implant appearance of the upper denture reference to the establishmentof the normal adult male maxillary central incisors.In this study, loading point for the maxillary central incisors edge midpointload size from0N gradually been increased to over1000N-. The direction ofthe force of the long axis of the implant into0degrees,30degrees,45degrees,60degrees,75degrees,90degrees rule change (coefficient of friction μ=0.3,the amount of interference1mm compressive stress170MP. tensile stress30.the MP, M-ISES stress600MP).Result：Range of values calculated by computer implant in the micro for150μm,by the force of the long axis of the vertical teeth, the implant neck force valueof29Newton, the central force of45Newton implant, implant roots force Avalue of117Newton. Implant a force parallel to the tooth long axis, the forceof the implant neck is210Newton, the implant Central force value of285Newton450Newton of the value of the implant roots force.75degrees, the implant by force and tooth long axis of the implant neckforce value of29Newton, implant the central force of45Newton, implantroots force of113Newton.60degrees, the implant by force and tooth long axisof the implant neck force is30N implant central force is48Newton, implantroots force of115Newton.45degrees, the implant by force and tooth long axisof the implant neck force value of35Newton implant Central force is55 Newton130Newton of the value of the implant roots force.30degrees, theimplant by force and tooth long axis of the implant neck force is45N, implantCentral force value of70Newton,160Newton of the value of the implant rootsforce.15degrees, the implant by force and tooth long axis of the implant neckforce value of73Newton implant Central force is110Newton,225Newton ofthe value of the implant roots force.Conclusion：Immediate loading of the anterior teeth implants without the formation ofbone resorption by different direction of the force, the maximum criticalocclusal force values into a curve.(1) When the implant by the load parallel tothe tooth long axis of the implant move150μm displacement caused by theabsorption of bone stress than roots in the neck bone, the bone is subject to thestress value is smaller.(2) When the implant by the perpendicular to the toothlong axis of loading, the implant move150μm displacement caused by theabsorption of bone, neck bone stress is smaller than the domestic demand byroots of bone stress values.(3) With the implant by the force along the toothlong axis of the constant changes, including15degrees,30degrees,45degrees,60degrees,75degrees, the implant mobile150μm displacement caused by theabsorption of bone, neck bone needed within the stress is always affected bythe stress value than the domestic demand in the root of bone.The above conclusions can explain the implant by external forces causedby bone resorption, the neck of the implant is only a small stress can causebone resorption, and the neck of the implant is often ahead of other parts of the implant began to absorb, absorb the extent will be more serious than other partsof the implant (central and roots) a lot.The calculation of the anterior teeth implants immediate loading, beforethe formation of bone resorption, dental implants can withstand the force size.Reveal the implant150μm displacement occurs, the implant by the force (forcein all directions). The dental implant under abnormal bite force, will producethe absorption of bone, revealing the reasons for the failure of dental implant.For the improvement of long-term success rate of dental implant, provides auseful occlusal force values range.