Effect of dowel length on the retention of two different prefabricated posts

Objectives

To compare the in vitro retentive values of stainless steel, parallel sided posts to quartz fiber tapered posts for two different dowel lengths (5mm and 10mm).

Methods

Both post systems were cemented with a dual-cure adhesive resin cement. Single rooted extracted human teeth (n-40) were de-coronated and randomly divided into 4 groups of 10 samples each. Posts of 5 and 10mm in length were luted with the resin cement. Each sample was placed on a universal testing machine, and using a push-out method, a vertical load was applied at a crosshead speed of 2mm/min. The amount of force required to dislodge the post was recorded. The effect of post type and length was evaluated using a 2-way analysis of variance.

Results

A statistically significant main effect was found for post length (P<.001) with the 10mm posts of both post systems requiring greater force to dislodge than the 5mm posts. There was no interaction between post length and post type (P>.05).

Conclusions

It is concluded from this study that there is no statistical difference in retention between quartz fiber tapered posts (D. T. Light-Post; RTD, St Egreve, France) and stainless steel parallel-sided posts (ParaPost, Coltene Whaledent, Cuyahoga Falls, OH USA) when they are cemented with the same resin cement (P> .05). The study also concludes that adequate retentive values are achieved with both systems at the shorter, 5mm post length.