Restoration of maxillary premolars: a finite element analysis of three repair methods and four kinds of dental restoration materials / 中国组织工程研究

ABSTRACT

BACKGROUND:Prognosis in tooth restoration is affected by different repair methods due to the different biomechanical effects.OBJECTIVE:To analyze three kinds of repair methods and four kinds of repair materials by using three-dimensional finite element analysis.METHODS:Tomographic images of isolated human maxillary first premolars were obtained by Micro CT scanning with a thickness of 0.019 mm.The Mimics output point cloud was used to generate the surface in Geomagic studio and the tooth model was generated respectively.The model was introduced into ABAQUS 6.13 software for Boolean operation,to simulate Inlay,Onlay of the medullary cavity retention type,and Core & Crown repair model.After the grid was divided into four ways of mechanical loading,six-point vertical loading or two-point loading at an angle of 0°,45°,90° with the long tooth shaft was done.The loading force was 75 N at each point.Four repair materials,cobalt-chrome,pure titanium,zirconia,IPS e.MAX,were used in this study.RESULTS AND CONCLUSION:(1) Under the four loading conditions of the same material,the maximum principal stress in the remaining dentin after Inlay restoration was the highest,followed by the Onlay repair and Core&Crown group.(2) Under the four loading conditions via the same approach,the maximum principal stress of the cobalt-chrome alloy in the enamel was the largest,and that of the IPS e.MAX porcelain was the smallest after repair.(3) The stress distribution of the parts was uniform after tooth restoration with the Core & Crown and the Onlay.To conclude,from the stress distribution,the Core&Crown and the Onlay are two ideal methods.Moreover,from the aspects of stress distribution and dentin preservation,Onlay is a more rational and safer way for large-area tooth defects.