title: [Measurement and analysis of optical density in dentine of 32 primary teeth].
abstract: OBJECTIVE
  To study the optical density (OD) of primary dental dentine and provide data for further research.
  
  
  METHODS
  The Digora system of dental digital radiography was used to acquire digital radiographic images of cross sections from 32 deciduous maxillary central incisors, and to measure the OD values of different depth (outer, middle and inner layers) and four sides (mesial, distal, labial and palatal sides) in dentine. The difference was analyzed with one-way ANOVA and SNK using SAS 6.12 software package.
  
  
  RESULTS
  The OD value of inner layer dentine was significantly lower than that of outer and middle layers (P=0.002), but there was no significant difference among four sides of dentine (P=0.0997).
  
  
  CONCLUSIONS
  OD value is an indirect physical quantity of dental mineralization, it provides a convenient digital indicator for the research of dental hard tissues.
authors.affiliation: Department of Pediatric Dentistry, College of Stomatology, Tongji University, Shanghai 200072, China. liudan@mail.tongji.edu.cn
authors.forename: Dan
authors.initials: D
authors.lastname: Liu
authors.forename: Fang
authors.initials: F
authors.lastname: Yu
authors.forename: Yu-mei
authors.initials: YM
authors.lastname: Zhao
mesh_terms: D003804:Dentin; D006801:Humans; D007180:Incisor; D008964:Molar, Third; D055095:Optics and Photonics; D014094:Tooth, Deciduous