CBCT测量上前牙区唇侧釉质厚度的临床研究

Clinical study on the labial enamel thickness of maxillary anterior teeth by CBCT

目的:利用CBCT测量上颌前牙的唇侧釉质厚度。方法:收集口腔颌面部CBCT影像数据140例,采用Mimics 21.0软件测量计算上前牙唇侧颈1/3、中1/3、切1/3釉质平均厚度,并测算常规贴面牙体预备后釉质剩余量。结果:上颌前牙区唇侧釉质厚度值自颈部1/3至切端1/3逐渐增大,不同牙位颈1/3处釉质厚度值自中切牙至尖牙有逐渐减小趋势,中1/3及切1/3相对较平稳。不同年龄组间前牙唇侧釉质厚度差异有统计学意义(P<0.05)的位置为:上颌中切牙切1/3,上颌侧切牙颈1/3,其余测量位点均无统计学差异。通过贴面牙体预备后釉质剩余量的测算显示牙本质暴露发生率均不超过1.5%,当加大贴面预备量时,颈部牙本质暴露的风险将升高。结论:使用CBCT测量前牙区唇侧釉质厚度的方法安全可靠;上颌前牙区唇侧颈部釉质较薄,行贴面牙体预备时,应注意权衡牙本质暴露风险。

Objective:To investigate the labial enamel thickness of maxillary anterior teeth based on cone beam computed tomography(CBCT)images.Methods:CBCT images from 80 young people were collected, after importing those images into Mimics 21.0 software in DICOM format and measuring the labial enamel thickness in the gingival l/3,middle 1/3,and incisal 1/3 sites separately, the data were then analyzed by SPSS 20.0 software.Results:The labial enamel thickness of maxillary anterior teeth gradually increased from gingival 1/3 to incisal 1/3,and gradually decreased from the central incisors to the canine in the site of gingival 1/3.Statistical differences of enamel thickness(P<0.05)were found at two sites between different age groups.The incidence rate of dentin exposure after veneer preparation with textbook standard is very low.However, when the preparation depth is increased, the gingival 1/3 tends to show the highest dentin exposure rate.Conclusion:Using CBCT to measure the thickness of labial enamel in maxillary anterior teeth is safe and reliable.The site of gingival 1/3 in labial enamel of the maxillary anterior teeth is thin, so it should be taken care of the highest dentin exposure rate when making veneers on teeth.