TY - JOUR AU - Zeng, Xiamei AU - Wang, Hairui AU - Chen, Yinyin AU - Zheng, Yanfen PY - 2022/10/12 Y2 - 2024/03/29 TI - Effects of instrumentation, root canal obturation and fiber post application on dentin crack initiation: instrumentation, root canal obturation and fiber post application JF - The Ethiopian Journal of Health Development JA - EJHD VL - IS - SE - Original Articles DO - UR - https://ejhd.org/index.php/ejhd/article/view/5067 SP - AB - <p><strong>Aim: </strong>The objective of this investigation was to evaluate the occurrence of fracture initiation in root dentin following root canal instrumentation, filling, and fibre post application. <strong>Methods:</strong> 150 extracted premolars were chosen at random and grouped into four major groups with 15 subgroups (n=10): group 1 (n=10), control, not instrumented; group 2 (n=20), the half were prepared to WaveOne size 25# or 40# respectively; group 3 (n=40), prepared same with group 2, then each subgroup was further divided with one half filling with lateral compaction or continuous wave compaction respectively; group 4 (n=80), prepared and filled same with group 3, then the lateral and continuous wave compaction groups were respectively divided by restoration with RelyX<sup>TM</sup> or RTD fiber posts. All roots were split perpendicular to the long axis at three points: 3 mm, 5 mm, and 7 mm from the apex, and then examined using a stereomicroscope. Cracks were counted and statistically examined based on their lack or presence. <strong>Results:</strong> No cracks were observed in unprepared and the only instrumented groups. Fiber post application significantly increased the crack formation (<em>P</em> &lt; .05). Lateral compaction filling caused significantly more cracks than continuous wave compaction after fiber post application (<em>P</em> &lt; .05). The cracks increased by the two kinds of fiber post showed significant difference. <strong>Conclusions:</strong> Fiber post space preparation mainly contributes to the dentin crack formation. When combined with fiber post application, continuous wave compaction produced less dentin cracks compared to lateral compaction filling.</p> ER -