The Effect of Ferrule Designs on the Fracture Resistance of Endodontically Treated Premolars

摘要

This study evaluated the effect of different ferrule designs on fracture resistances and failure modes of endodontically treated mandibular premolars restored with post-core and crown. Fifty mandibular premolars were randomly divided into five groups (n=10). Group 1 had a 2 mm circumferential ferrule. Group 2 had a 2 mm ferrule on the buccal side. Group 3 teeth had a 2 mm ferrule on the lingual side. Group 3 had a 2 mm ferrule on the mesial side. Group 5 had a 2 mm ferrule on the distal side. All the teeth were endodontically treated and restored with fibre posts and composite core build up followed by non-precious metal crowns. A compressive load at a crosshead speed of 0.5 mm/min, 25° to the long axis of the tooth and 2 mm from the central fossa towards the buccal cusps was applied. Failure loads and modes were recorded. Group 3 has significantly higher fracture resistance than group 2. The mean fracture resistances were not statistically significant among the rest of the groups. There was no significant association between ferrule designs and failure mode. In conclusion, Teeth with lingual ferrule alone have better fracture resistance compared to those with buccal ferrule alone.