Vertical fracture of root filled teeth restored with posts: the effects of patient age and dentine thickness

To determine whether patient age contributed to the fracture resistance of teeth subjected to root canal treatment and post placement.

Forty-five single-rooted, single-canal human teeth were mounted, instrumented, obturated and prepared for a post. The teeth were divided into young (18 < or = age < or = 35) and old (60 < or = age) groups and subjected to cyclic loading until fracture; those reaching 200,000 cycles without undergoing failure were then subjected to static loading to fracture. Statistical differences between groups were examined using one-way anovas, and correlations were identified using Pearson's r; significance was established at P < or = 0.05.

There was no significant difference between the two age groups in terms of the number of cycles to fracture (P > 0.05) or the load to fracture (P > 0.05). However, there was a significant correlation (P < or = 0.05) between the root fracture resistance and individual age, indicating that the susceptibility to root fracture increases significantly with increasing patient age. Also, the dentine thickness of roots that fractured was significantly less than those that did not (P = 0.04).

Vertical root fracture of teeth receiving root canal treatment with posts is more likely to occur in the teeth of older patients (60+) and particularly in those with low dentine thickness.