Research On Robot-assisted Tooth Preparation Based On Augmented Reality

Dental caries,as one of the three major human diseases,is an important cause of dental defects,which seriously affects people's oral health.Dental restoration is an important method for treating dental defects.Dental preparation is a necessary treatment link in the restoration process,which refers to the operation of a doctor to quantitatively remove the teeth at the caries and form the expected three-dimensional shape.In the traditional dental preparation process,a large number of repetitive fine adjustments are required to rely on manual operations by doctors and combined with rich clinical experience.However,the current imbalance of doctor-patient ratio in China cannot meet the current huge demand for dental preparation.Therefore,it is necessary to introduce robots and auxiliary software to replace or assist doctors in completing dental preparation work efficiently,which can not only alleviate the imbalance between doctors and patients,but also effectively improve the quality of prepared teeth and the effect of oral treatment.In this paper,the following researches are carried out in response to existing problems.Based on the oral survey report and actual requirements,this paper determines the type of posterior crown as a preparation,analyzes the operating characteristics of the doctor's preparation process,determines the specific requirements for posterior crown preparation,and clarifies the design requirements of the robot.According to the actual needs and design requirements in tooth preparation,the selection of the robot body and the design of the end effector were completed,and the corresponding threedimensional model is drawn according to the structure of the robot.The kinematics analysis of the tooth preparation assistance robot is completed by establishing the posture relationship between the robot and the teeth and solving the forward and inverse kinematics.According to the robot function determined by the preparation process of the posterior crown,the adjacent teeth preparation phase is planned as the robotic threedimensional curve planning,and the functional bevel phase is planned as the robotic three-dimensional surface planning.Firstly,by pre-processing the standard posterior crown full crown preparation model,the extraction criterion of the adjacent preparation curve is determined,and the standard adjacent preparation curve data is obtained.The back calculation and interpolation of the adjacent surface preparation curve were completed,and the robot trajectory planning of the adjacent surface preparation curve is realized.In the phase of the functional bevel,the surface map and constraints are constructed using the surface mapping relationship to determine the value points on the surface.The functional bevel is divided into three surfaces according to the adjacent relationship and function between the teeth.The interpolation of the three surfaces is completed and the preparation trajectory planning of the three surfaces is obtained according to the surface shape points and the surface patch characteristics.The registration method,implementation method,development platform and software function of the augmented reality and the assistant software for tooth preparation based on augmented reality are determined and developed by analyzing the key technologies of augmented reality in medicine and the methods of implementing augmented reality in medicine.The development of augmented reality is completed based on the AR Foundation.The design of the software UI,real-time interaction,and Bluetooth communication is completed based on this core program.The release of dental preparation assistance software is completed in Unity3 D,and the APP test was completed on the Android mobile device.The preset function and expected effect are achieved.In this paper,the preparation of experimental materials is completed,and a tooth preparation robot and its experimental equipment are set up for verification experiments.According to the planned robot trajectory,dental preparation experiments are completed in the preparation phase of the adjacent surface and the phase of the functional bevel.The feature points of the adjacent surface preparation phase and the functional bevel phase are selected,and the system error and random error between the theoretical characteristic points and the experimental measurement results are analyzed to verify the feasibility of the tooth-assisted robot preparation system.