Study On Location Error Of Surgical Guide And Its Effect To Implant Accuracy

The implant has become a preferred choice for edentulous restoration,which is beneficial for aesthetic effect and less damage to adjacent teeth.The important anatomical structure such as nerve,roots of adjacent teeth should be kept away from the implantation.The necessary condition for osseointegration is the sufficient bone around implant.Meanwhile,direction and angle of implantation play a significant role in restoration.A scientific implant plan and accuracy implant position are hard to achieve in the traditional implantology,which mainly depend on the experience of clinician.It rises risks and may lead to failure of implant surgery.The computer guided implantology has supplied the gap of tradition method in some respects,which is based on three-dimensional design and surgical guide.Comparing with the traditional implant method,the accuracy of computer guided implantology has been improved.However,it still has a large room for improvement.As the guide is the key of implant surgery,the error such as data acquisition,surgical plan and manufacture are accumulated on the guide.The location accuracy of surgical guide has a direct impact on the implant precision,and it may cause the deviation of the implantation.The purpose of this study is to construct a method to evaluate location error of surgical guide,which is described by implant deviation.Firstly,an analysis method for location error used in triangle mesh surface fitting was constructed.Secondly,the influence of surface error and layout were researched.Thirdly,some guides with specific located surface were manufactured and surface error was analyzed.Fourth,experiment and simulation were done to analyze location error of surgical guide.The main work and research results are as follows:1.Proposing a method of location error analysis for triangle mesh surface fitting,and Jacobian matrix was solved.2.Building a evaluate method of surface error,and presenting basic principle for the conversation between surface and located points,the impact of surface layout and error was discussed.3.Evaluating surface error of surgical guides with specific located surface.The results show that there has no significant error difference between different position of located surface.And the mean deviation of surface was 0.169 mm.4.Evaluating location error of surgical guide by experiment and simulation.The deviation at the hex of implant was larger than deviation at the apex,and all these deviation were close to 1mm.In addition,location error was positive correlation with surface error under the same layout.And it has no linear correlation with the surface layout.