Influence of Post Angulation between Coronal and Radicular Segment on the Fracture Resistance of Endodontically Treated Teeth

To evaluate the fracture resistance of proclined endodontically treated teeth with different post and core systems: In vitro study

Aim:

This study was aimed to evaluate the fracture resistance of proclined endodontically treated teeth with different post and core systems.

Settings and Design:

Experimental in vitro study.

Methodology:

Eighty extracted maxillary central incisors were selected and decoronated keeping 2 mm of crown ferrule and were endodontically treated. Postspace was prepared retaining 5 mm apical gp using peeso 3. Samples were divided into two groups. In Group 1, Wax pattern fabricated to accommodate different core angulations to be casted with Ni-Cr alloy. In Group 2, ever stick posts were angulated and cemented followed by porcelain fused to metal crown cementation for both the groups. Samples were thermocycled and subjected to the universal testing machine.

Statistical Analysis Used:

One-way ANOVA and Tukey’s post hoc test were used to compare the mean fracture resistance between different angulations in cast post and ever stick posts. Student’s paired t-test was used to compare the mean fracture resistance between cast post and everstick posts for each angulations. P value was set at P < 0.05.

Results:

The fracture resistance was the highest at 20° and lowest at 30° core angulations in both the groups.

Conclusions:

Changing core angulation up to 20° can be carried out safely using any of the post systems tested in the study. Core angulations >20°, should be used with caution, especially in patients with abnormal parafunctional habits and occlusal trauma.

Fracture Resistance of Tilted Premolars Restored with Different Post-Core Systems

Aims and Objective:

To assess the effect of root tilt on the fracture resistance and failure pattern of endodontically-treated premolars restored with different post-core systems.

Materials and Methods:

Ninety endodontically-treated premolars were mounted in acrylic blocks with 0°, 12°, and 24° axial root tilt. Teeth in each group were restored in three subgroups with cast post-core, readymade metal posts and composite cores, and fiber post and composite cores. Crowns of all teeth were prepared coinciding with the long axis of the acrylic blocks to receive all-ceramic crowns. All restored teeth were stressed to record the maximum load at failure and the associated failure pattern. The collected data were statistically analyzed using two-way ANOVA, Tukey's, and Kruskal–Wallis tests at α = 0.05 on past software to detect any differences between subgroups.

Results:

Analysis of the collected data indicated significant differences between the tested subgroups (ANOVA, P = 3.86). Further analysis showed significant difference between all test subgroups and the control (Tukey's, P < 0.05). In general, teeth with 0° tilt seemed more resistant to fracture than the tilted ones. For all groups, teeth restored with fiber post and composite cores (SG3) were more resistant to fracture compared to other post-core systems (SG1 and SG2) (Tukey's, P < 0.05). The root fracture was the most commonly seen mode of failure.

Conclusions:

Root tilting usually affects the fracture resistance of teeth restored with post-core systems. The fiber post and composite cores seemed to be the best choice to restore teeth with different root tilting possibilities.