title: Volumetry of human molars with flat panel-based volume CT in vitro.
abstract: The flat panel-based volume computed tomography (fpVCT) is a new CT device applicable for experimental, three-dimensional evaluation of teeth at a resolution of about 150 microm in the high contrast region. The aim of this study was to investigate whether fpVCT was suitable for quantification of the volumes of dental hard tissues and the root canal system to establish a new method for morphological studies. Fifty-two extracted third molars (maxillary: 31, mandibular: 21) were examined with a prototype of an fpVCT using a volumetry algorithm at different levels according to the radiographic density of enamel and dentine. Volumetry of the root canal system was performed after "region growing segmentation": starting from a voxel in the centre of the root canal, this algorithm searches voxels of same density in the surrounding. The volumetry of the root canal system was stopped by the investigator at the apical constriction. Results showed that dentine, enamel and root canal system could be well distinguished in three-dimensional images. Volumetry yielded the following data (cm(3), mean+/-SD): dentine 0.438+/-0.111, enamel 0.227+/-0.051, root canal system 0.052+/-0.017 and total volume 0.753+/-0.159. In conclusion, the fpVCT is appropriate for non-destructive volumetry of large numbers of teeth in experimental laboratory studies.
authors.affiliation: Department of Operative Dentistry and Periodontology, University of Freiburg, Hugstetter Str. 55, 79102, Freiburg, Germany. Christian.hannig@uniklinik-freiburg.de
authors.forename: Christian
authors.initials: C
authors.lastname: Hannig
authors.forename: Eva
authors.initials: E
authors.lastname: Krieger
authors.forename: Christian
authors.initials: C
authors.lastname: Dullin
authors.forename: Hans-Albert
authors.initials: HA
authors.lastname: Merten
authors.forename: Thomas
authors.initials: T
authors.lastname: Attin
authors.forename: Eckhardt
authors.initials: E
authors.lastname: Grabbe
authors.forename: Gabert
authors.initials: G
authors.lastname: Heidrich
mesh_terms: D015502:Absorptiometry, Photon / Q000295:instrumentation / Q000379:methods; D000465:Algorithms; D003743:Dental Enamel / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D003804:Dentin / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional / Q000295:instrumentation* / Q000379:methods; D008964:Molar, Third / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D009811:Odontometry / Q000295:instrumentation* / Q000379:methods; D010865:Pilot Projects; D012984:Software; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods; D014963:X-Ray Intensifying Screens