Performance of laser fluorescence for the detection of enamel caries in non-cavitated occlusal surfaces: clinical study with total validation of the sample.

PURPOSE: To evaluate the clinical performance of a laser fluorescence device in detecting enamel caries in non-cavitated occlusal surfaces. METHODS: The sample included 96 first and second permanent molars, selected according to the criteria of Ekstrand: 44 not suspected of having dentin caries (score: 0-2) and 52 under suspicion (score: 3-4). Once measured by laser fluorescence, all teeth were validated by fissurotomy (gold standard). To avoid ethical questions, the 44 teeth (score: 0-2) used were to serve as abutments for a fixed dental prostheses. Following fissurotomy, the 52 teeth with suspected caries were treated with resin composite restorations. Kruskall-Wallis statistical analysis (P<0.05) was used. RESULTS: Laser fluorescence showed an area under the Receiver Operating Characteristic (ROC) curve of Az = 0.803 for enamel caries. The cut-off point with the highest sensitivity and specificity was 15, with a sensitivity and specificity of 0.97 and 0.63, respectively. Values under 10 indicated healthy teeth.

Critical diameter of apical foramen and of file size using the Root ZX apex locator: an in vitro study.

INTRODUCTION: An evaluation was made of the accuracy of the Root ZX apex locator (J. Morita Corp, Tokyo, Japan) in widened foramina, considering the existing controversy over this issue in the literature. METHODS: Ten single-root teeth were embedded in an alginate mold. The foramina were widened from 0.6 mm to 1.0 mm. The measurements were taken with all possible file sizes ≥#10. The statistical accuracy of the Root ZX was calculated for the different diameters and for the influence of file size. RESULTS: The accuracy of the Root ZX apex locator with a range of error of ±0.5 mm was 87% in an apical foramen size of 0.6 mm and 84% using files size 45 or larger in an apical foramen size of 0.7 mm. With a tolerance of ±1 mm, the accuracy was 99% in an apical foramen size of 0.6 mm, 98% using files size 45 or larger in an apical foramen size of 0.7 mm, and 95% using files size 70 or larger in an apical foramen size of 0.8 mm. In the rest, accuracy was not certain. The measurements taken with smaller files were shorter. There were no cases of overestimation of the working length. CONCLUSIONS: The Root ZX apex locator was accurate for an apical size of 0.6 mm, independently of the file size; between 0.7 to 0.8 mm, we should adjust the files to the foramen, whereas above size 0.9 mm the locator is not accurate. The results show that the accuracy of this electronic apex locator is gradually lost as the foramen widens. Considering the stable conditions of in vitro studies, our findings advise caution in clinical application of the locator.

Developments in polymerization lamps.

Polymerization shrinkage of composite resins and the consequent stress generated at the composite-tooth interface continue to pose a serious clinical challenge. The development of high-intensity halogen lamps and the advent of curing units providing higher energy performance, such as laser lamps, plasma arc units, and, most recently, light-emitting diode (LED) curing units, have revolutionized polymerization lamp use and brought major changes in light-application techniques. A comprehensive review of the literature yielded the following conclusions: (1) the most reliable curing unit for any type of composite resin is the high-density halogen lamp, fitted with a programming device to enable both pulse-delay and soft-start techniques; (2) if any other type of curing unit is used, information must be available on the compatibility of the unit with the composite materials to be used; (3) polymerization lamp manufacturers need to focus on the ongoing development of LED technology; (4) further research is required to identify the most reliable light-application techniques.

Comportamiento de la intesidad de la luz de las lámparas halógenas y leds a través de la resina compuesta / No disponible

Objetivo: Describir el comportamiento de la Intensidad de la Luz generada por lámparas Halógenas y LEDs a medida que atraviesan laresina compuesta. Material y metodo: Utilizamos dos lámparas LEDs con intensidades de radiación de 350 y 210 mW/cm2 y dos lámparas Halógenas con intensidades de radiación de 460 y 300 mW/cm2 . Realizamos mediciones de intensidad mediante radiómetros en muestras entre 0.5, 1,1.5, 2, 2.5 y 3 mm de espesor. Resultados: El descenso de la intensidad es proporcional a la Intensidad de Salida y similar para todas las lámparas, excepto para la LEDs de mW/cm2 que es algo mayor. Conclusiones: El comportamiento de la Intensidad de Radiación a distintos planos de profundidad es similar para las lámparas Halógenas y LEDs estudiadas (AU)

Objective: To describe behaviour of light intensity trough a composite resin when it is generated by an halogen lamp and a LED lamp. Material and method: We used two LED lamps with radiation intensities of 350 and 210 mW/cm2 and two halogen lamps with radiation intensities of 460 and 300 mW/cm2. With a radiometer we measure light radiation every 0.5mm between 0.5mm and 3mm depth. Results: decrease in light intensity was proportional to intensity output and similar in all lamps, except for the LED lamp with 350mW/cm2 output in which it is larger. Conclusion: Intensity radiation behaviour trough composite is similar for halogen lamps and LED´s (AU)