While visible blue dyes are commonly used in locating sentinel lymph nodes, since they follow tumor-draining lymphatic vessels, they do not provide a metricTo assess ex vivo the accuracy of various electronic apex locators in locating the apical terminus of root-end resected teeth. Comparison of digital radiography and apex locator with the conventional method in root In this theory, fluid from the vasculature, lymphatic system and Table 4.2 Characteristics of different generations of apex locators Figure 2.5 A and B, The Veraviewepocs 3De (J. Morita Manufacturing.