Fig. 14

Effective preparation of root canal files. Reproduced with permission. Source: USPTO, www.uspto.gov: CNIPA, www.cnipa.gov.cn. a Process of using the electronic apical locator. B–d Root canal files for measuring root canal length [122–124]. e Root canal files with exposed window [125, 126]. f Structure to prevent disturbance [127]. g Structures limiting the working length of root canal files [128]. h Microscope working schematic [129]