Clinical Study On The Labial Enamel Thickness Of Maxillary Anterior Teeth By CBCT

Objectives: The purpose of this study was to investigate the labial enamel thickness of maxillary anterior teeth based on Cone Beam Computed Tomography(CBCT)images,and to provide reference for clinical veneer restoration.Methods:1.Oral and maxillofacial CBCT images were collected from Department of Radiology,the Third Hospital of Hebei Medical University,from January to December 2019,including 80 young people(ages 30.8±7.09),60 middle-aged people(ages 51.6±3.92).2.Imported those images into mimics21.0 software in DICOM format and measured the labial enamel thickness in the gingival l/3,middle 1/3,and incisal 1/3 sites separately.3.All the data were analyzed by SPSS20.0 software.The thickness of enamel at different sites in different age groups and gender groups were analyzed by independent sample t-test,and the residual enamel thickness after veneer preparation with textbook standard(reducing 0.3mm in gingival 1/3,0.5mm in middle 1/3,0.7mm in incisal 1/3)were analyzed too.Results: 1.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,the enamel thickness in the site of incisal 1/3 and middle 1/3 were relatively stable.2.Statistical differences of enamel thickness(P < 0.05)were found at two sites between different age groups,including the incisal 1/3 of the maxillary central incisor and the gingival 1/3 of the maxillary lateral incisor,and there was no statistical significance in the other sites.3.There was no statistical difference in most of the measurement sites between different gender groups,except for the gingival 1/3 of the maxillary canine(P < 0.05).4.The theoretical 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.Conclusions:1.The labial enamel thickness of most maxillary anterior teeth meets the preparation standard of veneer,if the reduction needs to be increased,doctors should carefully consider the restoration plan and weigh the risk of dentin exposure.2.There was no significant difference on labial enamel thickness between male and female groups。3.The enamel thickness gradually decreased with age,particularly in the incisal 1/3 and the gingival 1/3,but the loss was very small.