Ru1ls: The root surface with high root caries prevalence rate are labial surfaces of incisor and canine, mandibular prem结果：根面龋易感性高的根面为前牙、下领前磨牙、磨牙的唇（颊）面、下前牙与上领磨牙的舌面、前磨牙的远中面、磨牙的近中面。