目的:研究放置时间及材料对三维打印光敏树脂牙列模型形态稳定性的影响.方法:两种常用光敏树脂材料(FHD1400、E-Model-Light)分别打印10副牙列模型,在完成打印即刻及放置1、3、7、14、28、60 d扫描成数字化三维模型,重叠生成不同时间点模型重叠热力图,测算平均偏差及变形百分比,测量牙弓前、中、后段宽度及长度随时间的变化量.结果:牙列模型随放置时间延长收缩变形加剧,平均偏差、变形百分比及牙弓长宽收缩量在14 d内迅速增加,14 d时牙弓后段宽度收缩大于0.2 mm,超过临床允许误差范围.所有时间点FHD1400组模型平均偏差及变形百分比显著大于E-Model-Light组(P<0.05).结论:两种临床常用光敏树脂材料牙列模型形态稳定性欠佳,E-Model-Light组稳定性优于FHD1400组,牙列模型从打印到使用不应超过14 d.
Morphological Stability of Three-dimensional Printed Photosensitive Resin Dental Models
Objective:To study the morphological stability of photosensitive resin dental models made from differ-ent three-dimensional printing materials.Methods:Resin dental models made from two types of 3D-printed materi-als were printed,namely FHD1400 group(10 sets)and E-Model-Light group(10 sets).All models were scanned by an optical model scanner instantly after printed and after 1,3,7,14,28,and 60 days of storage.The heat map was generated by superimposing models at different time points.The average deviation and deformation percentage were calculated,meanwhile,changes of four linear indexes(the anterior,middle,and posterior width and length of the dental arch)of the model were measured.The data were statistically analyzed and the differences were compared among the models.Results:The resin dental model shrunk more with the extension of storage time.The average deviation,deformation percentage,and contraction of arch length and width increased rapidly within 14 days.The width contraction between molars of all models exceeded 0.2 mm after 14 days of storage.Conclusion:The resin dental models printed from two commonly used clinical ma-terials have poor morphological stability and should not be used longer than 14 days after printing.The morphological stability of E-Model-Light group was better than that of FHD1400 group.