Critical appraisal of studies on dentinal radicular microcracks in endodontics: methodological issues, contemporary concepts, and future perspectives

Abstract

The dentinal radicular microcrack is a difficult clinical problem to diagnose and treat, and it is one of the most common reasons for tooth extraction. These microcracks start in the radicular dentin, and laboratory studies have linked crack formation to some routine endodontic procedures, namely root canal preparation, obturation, and retreatment. Most of these studies were performed using destructive methods, such as the sectioning technique, previously developed for the study of the internal anatomy of teeth. Nowadays, technological advances in the field of imaging may lead to a more thorough understanding of dentinal microcracks. This article seeks to critically appraise the methodological aspects involved in the study of dentinal radicular microcrack formation after root canal preparation, obturation, and retreatment.

Diagnosis of Vertical Root Fractures in Restored Endodontically Treated Teeth: A Time-dependent Retrospective Cohort Study

“…Earlier in vitro experimentation showed that VRFs may occur under spreader loads of 1.5 kg (33), whereas dentinal defects and craze lines can occur after lateral compaction (13). Although it has not been proven that lateral compaction can be a trigger for VRFs, it has been reported that lateral compaction is the most used technique of obturation in endodontically treated teeth with VRFs (34). However, the current study did not compare the influence of different root canal filling techniques on VRFs.…”

Incidence of microcracks after preparation of straight and curved root canals with three different NiTi instrumentation techniques assessed by micro‐CT

“…Moreover, the destructive nature of sectioning methods has several drawbacks such as evaluation of only 3-4 specific levels of the specimen with the chance of missing microcracks in other regions of the root. In summary, several authors concluded that root-sectioning methods and direct observation of root slices by optical microscopy present meaningful disadvantages that reduce the overall reliability of this experimental model (4,9,13,28). In summary, several authors concluded that root-sectioning methods and direct observation of root slices by optical microscopy present meaningful disadvantages that reduce the overall reliability of this experimental model (4,9,13,28).…”

“…Thus, an unpredictable quantity of undetected preoperative microcracks may be a reason for different results when comparing these studies (14). This technique is unable to detect craze lines and defects throughout the longitudinal axis of the root (4,13), and light reflections on the resected root surface may lead to false-positive results (27). This technique is unable to detect craze lines and defects throughout the longitudinal axis of the root (4,13), and light reflections on the resected root surface may lead to false-positive results (27).…”

Evaluation of Dentinal Defects After Different Root Canal Preparation Techniques

“…Vertikal kök kırıkları, endodontik tedavili dişlerde başarısızlığa neden olan önemli faktörler arasındadır 1,2,3 . Kök kanal şekillendirmesi sırasında kök yüzeyinde meydana gelen mikroçatlaklar, kök kırıklarının oluşmasında rol oynamaktadır 4,5 .…”