title: Assessment of enamel demineralization using conventional, digital, and digitized radiography.
abstract: This experimental research aimed at evaluating the accuracy of enamel demineralization detection using conventional, digital, and digitized radiographs, as well as to compare radiographs and logarithmically contrast-enhanced subtraction images. Enamel subsurface demineralization was induced on one of the approximal surfaces of 49 sound third molars. Standardized radiographs of the teeth were taken prior to and after the demineralization phase with three digital systems--CygnusRay MPS, DenOptix and DIGORA--and InSight film. Three radiologists interpreted the pairs of conventional, digital, and digitized radiographs in two different occasions. Logarithmically contrast-enhanced subtraction images were examined by a fourth radiologist only once. Radiographic diagnosis was validated by cross-sectional microhardness profiling in the test areas of the approximal surfaces. Accuracy was estimated by Receiver Operating Characteristic (ROC) analysis. Chi-square test, at a significance level of 5%, was used to compare the areas under the ROC curves (A(z)) calculated for the different imaging modalities. Concerning the radiographs, the DenOptix system (A(z) = 0.91) and conventional radiographs (A(z) = 0.90) presented the highest accuracy values compared with the other three radiographic modalities. However, logarithmically contrast-enhanced subtraction images (A(z) = 0.98) were significantly more accurate than conventional, digital, and digitized radiographs (p = 0.0000). It can be concluded that the DenOptix system and conventional radiographs provide better performance for diagnosing enamel subsurface demineralization. Logarithmic subtraction significantly improves radiographic detection.
authors.affiliation: Department of Pediatric Dentistry and Orthodontics, São Paulo City University.
authors.forename: Rívea Inês
authors.initials: RI
authors.lastname: Ferreira
authors.forename: Francisco
authors.initials: F
authors.lastname: Haiter-Neto
authors.forename: Cínthia Pereira Machado
authors.initials: CP
authors.lastname: Tabchoury
authors.forename: Guilherme Assumpção Neves
authors.initials: GA
authors.lastname: de Paiva
authors.forename: Frab Norberto
authors.initials: FN
authors.lastname: Bóscolo
mesh_terms: D003731:Dental Caries / Q000000981:diagnostic imaging*; D003743:Dental Enamel / Q000000981:diagnostic imaging*; D005240:Feasibility Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D015588:Observer Variation; D011237:Predictive Value of Tests; D012372:ROC Curve; D011856:Radiographic Image Enhancement; D019252:Radiography, Dental, Digital / Q000592:standards*; D015203:Reproducibility of Results; D017001:Tooth Demineralization / Q000000981:diagnostic imaging*