Root canals come in all shapes and sizes, including curved, straight, round, oval, and so on. In elderly people, there is calcification of the tooth itself, which can be interpreted as the cavity in which the nerve and blood vessels travel becomes narrower and narrower with age, forming something like a calculus. When the calculus forms, it blocks the root canal, and the root canal will not be accessible when treatment is done. If the canal is completely blocked and there is no inflammation under the root, the blockage is not a cause for concern. If there is already inflammation under the root of the tooth, there is no good way to pass the tooth open due to calcification. Some of the tooth inflammation and bacteria can not be cleaned up well, which may lead to bacteria reproduction and inflammation at a later stage, resulting in neuritis symptoms such as pain when exposed to cold or hot sensations. If the root canal is not open during the root canal treatment, or if the root canal is not open and a treatment is completed, there may be inflammation under the root of the tooth at a later stage, and it may be painful to bite something, or the gums may be swollen or swollen. If there is still some calcification that is more complete, the whole root canal is not accessible, but basically blocked by calcification, and if there is no bacteria present in the blocked part, the prognosis is actually relatively good. There is no way to determine the prognosis, in the treatment process, only through the treatment, the degree of inflammation to determine the prognosis, need to be observed for about three months, if the healing is not a big problem, if not healed, need to consider further surgical treatment.