Effect of tapering internal coronal walls on fracture resistance of anterior teeth treated with cast post and core: In vitro study

Abstract

When fabricating indirect post and core, internal coronal walls are tapered to remove undercuts and allow a better adaptation. To evaluate the fracture strength of anterior tooth reconstructed with post and core and crowned, with two different taper of internal coronal walls, 6° and 30° to the long axis, two groups of 30 clear plastic analogues simulating endodontically treated maxillary central incisors were prepared. The analogues crowned were subjected to a compressive load with a 1-kN cell at a crosshead speed of 0.05 mm/min at 130° to the long axis until fracture occurred. Data were analyzed by Lillifors and Mann–Whitney tests. Mean failure loads for the groups were as follows: group I 1038.69 N (standard deviation ±243.52 N) and group II 1231.86 N (standard deviation ±368.76 N). Statistical tests showed significant difference between groups (p = 0.0010 < 0.01). Increasing the taper of internal coronal walls appears to enhance the fracture resistance of anterior maxillary teeth post and core reconstructed.

Impact of a Core Ferrule Design on Fracture Resistance of Teeth Restored with Cast Post and Core

“…Thus, dynamic or fatigue behavior cannot be inferred in clinical situations until proven. However, in the literature, the use of analogues to compare the fracture resistance is valid [ 68 – 71 ].…”

Comparative Analysis of Different Sizes of Prefabricated Metal Posts Placed in Relation to Premolars- A Retrospective Analysis

“…Parallel sided posts have more retention than tapered posts and longer, wider the posts, greater is its strength and retention. Yet,over enlargement of the channel for insertion of large diameter post may weaken the root because of loss of dentin and results in root fracture under functional load 19 .…”