基于3种不同数字化方法设计下颌第一磨牙咬合面的精度比较研究OA

Objective This study aimed to compare the accuracy of trajectory-based personalized parameters from a fully adjustable articulator,mandibular movement trajectories,and dynamic jaw relationships.These components were evaluated to guide the design of a mandibular first molar prosthesis.The occlusal surface of the prosthesis was digitally designed through model experiments.Methods A total of 12 volunteers(4 males and 8 females)meeting the inclusion criteria were recruited,with a mean age of 29.5 years.The 3Shape Trios 3 intraoral scanner was used to obtain the ma-xillary and mandibular three-dimensional dental models of the subjects.It was also utilized to apply the patient-specific motion function for capturing the dynamic jaw relationships during protrusive,left lateral,and right lateral movements.The Zebris JMA Optic and ModjawTM mandibular movement analysis systems were also used to similarly capture the mandibular movement trajectories during the protrusive,left lateral,and right lateral movements of the subjects.Perso-nalized parameters corresponding to the fully adjustable articulator were obtained based on the mandibular movement trajectories recorded by the Zebris JMA Optic system.The mandibular first molar in the original model was virtually prepared following the occlusal veneer tooth preparation standard using reverse engineering software to obtain the man-dibular working model.The occlusal surfaces of the occlusal veneers for the mandibular first molar were digitally de-signed with the help of fully adjustable articulator parameters(Articulator group),mandibular movement trajectories(JMA group,Modjaw group),and dynamic jaw relationships(PSM group)in the prosthetic design software.The occlu-sal surface morphology of the prosthesis designed by different methods was analyzed for deviation with the occlusal sur-face morphology of the original natural tooth of the subjects through reverse engineering software.The occlusal surface accuracy of the prosthesis designed by different methods was compared using several metrological indicators.Results The intergroup differences in average positive deviation among the Articulator,JMA,Modjaw,and PSM groups were not statistically significant(P>0.05).Meanwhile,the intergroup differences in average negative deviation,average de-viation,and root mean square were statistically significant(P<0.05).The average negative deviation in the Articulator group(-96.2±15.8)μm was greater than that in the JMA group(-160.1±44.4)μm,the Modjaw group(-141.6±33.2)μm,and the PSM group(-233.6±28.5)μm.The average deviation in the Articulator group(172.5±113.0)μm was greater than that in the JMA group(19.2±132.6)μm,the Modjaw group(70.3±121.3)μm,and the PSM group(-66.8±129.1)μm.Notably,the difference was statistically significant(P<0.05).Conclusion The occlusal surface morpholo-gy of the mandibular first molar prosthesis designed with the trajectory-based personalized parameters from a fully ad-justable articulator,mandibular movement trajectories,and dynamic jaw relationships differed from the occlusal surface morphology of the original natural tooth.Compared with the fully adjustable articulator parameters,the occlusal surface of the prosthesis designed with mandibular movement trajectories and dynamic jaw relationships were more effective in removing occlusal interference.