Gray scale inversion in digital image for measurement of tooth length

Abstract

The aim of this study was to assess the applicability of gray scale inversion in performing digital linear endodontic measurements. Standardized digital images were taken of 40 extracted human permanent single-rooted teeth with K-files size 15 placed at different lengths in the root canal, using the CDR Wireless ® digital system. All images were treated with Positive, a digital tool that inverts the grayscale value. Eight radiologists measured the distance between the lower limit of the rubber stop and the tip of the file on both original and positive images. After 15 days, they repeated this procedure in 50% of the image samples. The intra-and inter-examiner agreement was analyzed by intraclass correlation test, and the comparison between the two image groups and the actual lengths by the Student's t-test (α=0.05). Intra-and inter-examiner evaluation showed high reproducibility (r>0.95) of both original and positive images. No statistically significant differences (p>0.05) were found between measurements performed on original and positive images, but both differed significantly from the actual lengths (p<0.05). Gray scale inversion has low applicability in measuring endodontic files, since it did not improve the accuracy of measurements.

Can the Inversion Filter Improve the Visibility of the Mandibular Incisive Canal?

“…According to Paul et al application of IF enhanced the contours and made the image more easily recognizable by the human visual system ( 13 ). In addition, IF provides a negative image and sometimes reveals pathologies that mental area on panoramic radiographs in conventional mode ( 3 , 4 , 8 , 9 , 14 ), but so far there is no study about the effect of IF on the visibility of MIC.…”

Desempeño De Cuatro Métodos Estadísticos Para Evaluación De La Concordancia Prueba-Reprueba De Variables Continuas en Una Muestra

“…La mayoría de estos métodos incluyen pruebas de hipótesis (pruebas "t" de Student pareadas, análisis de varianzas-ANOVA) o coeficientes de correlación (Pearson y coeficiente de correlación intraclase) (18,22). Otros métodos incluyen análisis de regresión y el coeficiente de variación (23,24).…”

“…La prueba "t" de Student ha sido empleada frecuentemente para comparar promedios de una prueba (test) o incluso en estudios prueba re-prueba para saber si existe algún sesgo estadísticamente significativo entre las pruebas (22,28). Aunque es útil, no debe ser empleada como tal para la evaluación de la concordancia dado que el estadístico t no provee información sobre el nivel de precisión y exactitud entre las evaluaciones de las pruebas (o momentos de la prueba).…”

“…Esta variable se clasifica como una variable cuantitativa, continua de razón. Se definió como la distancia en milímetros (mm) desde el punto más apical radicular visible radiográficamente hasta el punto coronal más visible radiográficamente (22).…”

Influência do formato do arquivo e da compactação via transmissão online de imagens radiográficas digitais no diagnóstico de lesões de cárie

“…Para possibilitar a aquisição radiográfica, os dentes foram dispostos de forma aleatória aos pares, sempre um pré-molar e um molar, em fantomas radiográficos constituídos de um bloco feito à base de gesso e arroz triturado em uma proporção de 1:1, que simula o osso alveolar humano (Oliveira et al, 2012). Com o intuito de simular uma situação clínica, estes foram compostos também por dentes denominados de não-teste, complementares, sendo dois inferiores posicionados adjacentes aos dentes teste e quatro dentes representando a arcada dentária oposta.…”