Although many studies have looked at the mesiobuccal root of maxillary molars, the palatal root has not received as much attention, and in particular, no study has looked specifically at palatal root anatomy in regard to accurately determining working length for canal instrumentation and obturation.
UNCF redirects here. It is not to be confused with UNICEF. The United Negro College Fund, or UNCF, is an American philanthropic organization that funds scholarships for black students and general scholarship funds for 39 private historically black colleges and universities.
UNF (Unified Fine) is the same as UNC except that for each size of bolt, the number of threads per inch is higher, so the thread is finer. UNEF (Unified Extra Fine) is the same as UNF except that the number of threads per inch is even higher for each fastener size. UNF and UNEF fasteners are generally available only from industrial fastener suppliers. 4UN, 6UN, 8UN, 12UN, 16UN, 20UN, 28UN, and 32UN are thread series in which the number before the UN indicates the number of threads per inch.