THE EFFECT OF SERRATIONS ON CARBON-FIBER POSTS - RETENTION WITHIN THEROOT-CANAL, CORE RETENTION, AND POST RIGIDITY

The retention in root canals of serrated carbon fibre Composiposts and stainless steel Paraposts was tested under tensile load. Twenty unres tored human roots were endodontically prepared and root filled. Two gr oups of 10 roots received 1.4-mm Composiposts or 1.25-mm Paraposts lut ed with a resin cement. The specimens were then embedded in acrylic re sin and mounted in an Instron machine. The tensile force (kg) required to dislodge the posts was recorded and analysed with Student's t test . The results revealed that there was no significant difference in the retention of either post (P > .05). The rigidity of 10 1.4-mm serrate d Composiposts was tested in a three-point bend test in an instron mac hine, and the retention of composite cores to 10 of these posts under tensile force was also tested. The results from these tests were compa red to previous data from the authors' laboratory and revealed that th e serrations significantly reduced the rigidity of the post (P < .001) and increased the retention of a core material (P < .001).