Clinical Evaluation Of Cast Post And Core In Restorating Premolars And Molars Of Extensive Loss

Objective: To investigate the effect of cast post and core on the restoration of premolars and molars of extensive loss.Methods: Fifty six premolars and molars of extensive loss were treated with root canal therapy. After tooth and canal preparation, they were restored by cast post and core with indirect method. First, make the impressions and hard stone models. Then, make and invest the wax pattern on the hard stone models, and cast the cast post and core with the NPG medium fusing dental alloy. After the intra-oral adjustment, cement the cast post and core in the root canal. Then, prepare regularly, make sure an enough ferrule, make the impressions and hard stone models again, match the tooth color, send them to lab. In there, the special technicians make the base metal crown with the NPG high fusing dental alloy and make the porcelain fused to metal crown with VITA porcelain. Last, adjust and cement the crown. The restoration effect was evaluated at the 5th to 37th month.Results: The cast post and core can tightly connect with the remaining tooth tissue and root canal, fill the extensive loss of tooth tissue, and provide better retention and the anti-fracture ability for the crown. And the retention and the anti-fracture ability of cast post and core were satisfactory. During investigating the clinical case, except one root fracture case and two falling cases, the other cases are successful. The ratio of effective is 94.6%.inclusions: 1. The indirect method to make the cast post and core is convenience and precise.2. The design of ferrule is useful to prevent fracture of the root of the teeth.3. The cast post and core is a better method in treating premolars and molars of extensive loss.