• Sirirat Ananviriyaporn D.D.S.
• Prarom Salimee D.D.S., Ph.D.

Objectives To study the failure resistance of root canal treatment (RCT) teeth restored with post and
core using different diameters and lengths of fiber posts.

Materials and methods Thirty maxillary central incisors were divided into 3 groups. After
RCT-treated, spaces for post were prepared with drill #2. All groups were restored with fiber post
(D.T. light-post). The first group was restored with the size that properly fit the canal (post #2).
The second group used the post with the same canal length but smaller diameter (post #1). The third
group used the post that shorter than the canal length but bigger diameter that fit the cervical part of the
canal (post #3). After cementing with resin cement (Panavia F 2.0), core build-up with composite was
performed in each specimen, the teeth were embedded in self cure acrylic resin block. The samples
were loaded on a universal testing machine with a crosshead speed of 2 mm/min on the palatal surfaces
at 90 Ì angles to the long axis of the tooth until failure occurred.

Results Failure resistance of group 1, group 2 and group 3 were 108.33 ± 11.59 N, 79.08 ± 12.15 N
and 94.87 ± 14.48 N, respectively. ANOVA and Bonferroni test revealed that there was no significant
difference of the failure resistance between group 1 and group 3 (p > 0.05). But group 2 was significantly
different from the other groups (p < 0.05). No root fractures occurred in any of the experimental
groups.

Conclusion Root canal treatment teeth restored with fiber post that the diameter properly fit the
cervical part of canal, though the length was shorter, were significantly stronger than those restored
with the entire length of post but diameter was not fit the canal.

(CU Dent J. 2008;31:359-70)