抄録
The development of new dental materials and methods has enlarged the possibilities of composite resin cores. In this study we examined effects of prefabricated metal posts on reinforcement of composite cores and effects of post length and diameter on core retention. First, the bending test of both various prefabricated posts only and composite cores in which the stainless parallel posts (AD Post®) were embedded was carried out. Then, pull-out test of AD Posts which were built up with Panavia EX®in root canals of extracted human teeth was carried out.
The following conclusions were drawn:
1. The bending strengths of prefabricated posts were greatly different from the kind of metal to its shape. The tapered self-threading posts provided the weakest bending strength because they have deep grooves, whereas the stainless parallel posts provided the biggest.
2. It was confirmed by bending test that the prefabricated metal post reinforced composite resin core significantly.
3. The surface treatment, i.e. sandblasting with almina and/or application of resin adhesive, on the metal post had no significant effect on the reinforcement of composite cores.
4. The retentive force of AD Post increased gradually with increasing both its length and its diameter. Especially, the increase of diameter was more effective for increasing the retention.
