The Study On The Precision Of Digital Removable Partial Denture Framework Model

Objective:Obtaining accurate and stable digital model was the basis of producing 3D printing removable partial denture framework with good suitability and performance.To provide reference to clinical application,this experiment studied the acquisition method of digital removable partial denture framework model,analyzed its precision,and explored the data collection method and attentions of digital removable partial denture framework model.Method:A standard plaster model was selected from maxilla and mandible separately,and was named with maxilla group and mandible group based on the location of model.Using 3Shape^TM D700 digital model scanning system scanned maxilla and mandible group repeatedly,each group was scanned 10 times and 20 STL files were generated from format conversion.After aligning and analyzing deviation of STL files of digital model by Geomagic Studio 12.0 software,the“color spot chart&standard deviation&triangle quantity”report was obtained.Statistically analyzing the results,and exploring the correlation between accuracy of digital cast scanning system and triangle quantity.Results:1.3D standard deviations of maxilla digital model and mandible digital model:The maxilla group and mandible group were according with normal distribution.For maxilla group and mandible group,the 3D standard deviation was 0.041±0.011?m,and 0.052±0.018?m respectively.There was no statistical difference between them?p=0.148,p>0.05?.2.The correlation between the number of triangular mesh in digital model and the 3D standard deviation:The number of triangular mesh in maxilla digital model did not accord with the normal distribution,and the mesh number was180924.00?1060.00?.Besides,there was no correlation between triangle quantity and3D standard deviation?p=0.615,p>0.05?.The number of triangular mesh in mandible digital model was consistent with normal distribution,and the mesh number was176188.67±316.28.Besides,there was no correlation between triangle quantity and3D standard deviation?p=0.851,p>0.05?.Conclusion:By analyzing the comparison data of STL file obtained from multiple scanning of different models by digital scanning system,the result showed that the digital model collected by this scanning system had high precision,good stability,which could reach the requirements of RPD design and fabrication.