Preliminary Construction And Application Of Digital Evaluation System About Tooth Preparation

Objectives:The purpose of this study was to construct a digital evaluation system about convergence angle and reduction for tooth preparation by 3 shape Trios digital scanning systems?Geomagic Wrap 2017?Geomagic ControlX 3-dimensional(3D)software.It is beneficial for dental students to improve preparation quality in daily practice and education by the objective evaluation system.Methods:1.To construct a digital evaluation system about convergence angle and reduction for tooth preparation by 3 shape Trios digital scanning systems?Geomagic Wrap 2017?Geomagic Control X 3D software.2.To measure the convergence angle(CA)(buccolingual and mesio-distal views)and reduction(buccal surface?lingual surface?mesial surface?distal surface?occlusal surface)of tooth preparation for left mandibular first molar carried out by junior student at the Stomatology College of Kunming Medical University(KMU)by means of the above-mentioned assessment system.3.A total of 40 junior students at the Stomatology College of KMU were assigned to two groups:experimental group(EG)(n=20),control group(CG)(n=20).Students in the CG were taught by traditional methodologies while the experimental groups taught by objective digital assessment system.A comparation parameter of EG to CG was the convergence angle and reduction at different stage.The questionnaires of digital training system were answered by the students of EG.Results:1.A digital evaluation system about convergence angle and reduction for tooth preparation was constructed by 3 shape Trios digital scanning systems?Geomagic Wrap 2017?Geomagic ControlX 3D software.2.The mean CA was 21° that carried out by 40 junior students at the Stomatology College of KMU,the mean CA for buccolingual axial wall preparations(20.5°)was less than the mean CA for mesio-distal axial wall the preparations(21.5°).The area percentage of qualified reduction is significantly higher than that of unqualified reduction and standard reduction in buccal surface and lingual surface(p<0.05),while the area percentage of qualified reduction and standard reduction is significantly lower than unqualified reduction in other three surface(mesial?distal?occlusal)(p<0.05).3.It showed decreasing trend of CA of both CG and EG comparing to the CA before training,while there is no significant difference between two groups(p>0.05).4.The result showed an increasing trend of standard reduction and qualified reduction of EG in five surface after training while there was no regular changing in CG,And it is no significant difference between two groups(p>0.05).5.The questionnaire results from the students of the EG indicated more than 80%of the students hold positive attitude about digital assessment system,and they hope they could have the tooth preparation training aided by digital assessment system.Conclusion:1.It was a convenient and simple operation system of tooth preparation constructed by our study,convergence angle and reduction could be repeatedly evaluated qualitatively and quantitatively with the system.2.We can finish the measurement and assessment of the CA and reduction of tooth preparation for left mandibular first molar carried out by junior students at the Stomatology College of KMU by the digital evaluation system we had constructed.3.Both traditional teaching and digital feedback could improve the quality of the CA and reduction of tooth preparation during the training of tooth preparation.4.It can achieve the same training outcome as traditional teaching feedback aiding digital evaluation system,and also inspire students by increasing learning interesting and initiative.