Spatial resolution in radiometric analysis of enamel loss : a pilot study

• Published in: Oral surgery, oral medicine, oral pathology, oral radiology and endodontics oral medicine, oral pathology, oral radiology and endodontics, 1996-02, Vol.81 (2), p.245-250
• Main Authors: SHROUT, M. K, RUSSELL, C. M, POTTER, B. J, HILDEBOLT, C. F, GA, A
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Dental Caries - diagnostic imaging; Dental Caries - pathology; Dental Enamel - diagnostic imaging; Dental Enamel - pathology; Dentin - diagnostic imaging; Dentin - pathology; Dentistry; Humans; Image Processing, Computer-Assisted; Investigative techniques, diagnostic techniques (general aspects); Medical sciences; Organ Size; Otorhinolaryngology. Stomatology. Orbit; Pilot Projects; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Radiographic Image Enhancement; Radiometry; Tooth Abrasion - diagnostic imaging; Tooth Abrasion - pathology
• ISSN: 1079-2104; 1528-395X
• DOI: 10.1016/S1079-2104(96)80424-0

This pilot study was undertaken to determine whether spatial resolution affects radiometric analyses aimed at detecting progressive enamel loss. Four teeth were weighed, attached to a positioning device, and evaluated with radiography. A 1 mm strip of enamel was removed from each tooth, and the teeth were weighted again and reexamined by radiography. This process was repeated five times until 1/2 mm of dentin was removed. The radiographs were digitized twice with 59 and 200 microns pixels at 8 bits, providing two series of images with the optical densities converted into 256 gray levels. Each series of images was adjusted for contrast variation. Regions of interest were drawn on the crowns, and cumulative percent histograms (CPHs) were calculated. Within a series of CPHs enamel reduction resulted in shifts in the CPHs that were directly proportional to the amount of enamel removed. CPH shifts associated with the smaller 59 microns pixels accounted for 68% of the variation in weights caused by enamel reduction, whereas the shifts associated with the larger 200 microns pixels accounted for 50%. The results indicate that pixel size does affect radiometric determinations of enamel reduction.