Fracture Characteristics of Subtle Vertical Root Fracture in Endodontical Treated Tooth: An In Vitro Observation and Micro-CT Study

doi:10.13701/j.cnki.kqyxyj.2024.07.009

Abstract

Abstract: Objective: To collect endodontically treated teeth with subtle vertical root fracture (SVRF), to analyze the fracture characteristics through in vitro observation and micro-CT scanning, and to investigate their initiation and development. Methods: A total of 21 SVRF teeth extracted in our hospital from October 2021 to October 2023 were collected. The position of the teeth and the specific root where the fractures occurred were documented. The number of fractures (calculated separately for buccal, lingual, mesial, and distal sides) and the longitudinal distribution of fractures (divided into four categories based on involvement of the enamel-dentin junction and the apex) were recorded by direct observation or trans-illumination method. Micro-CT images were utilized to assess whether the fracture was involved the root canal, the direction of the crack in axial images (buccal-lingual, mesial-distal), and the widest fracture width of each tooth. The widest level on the root was categorized into upper, middle, and apical third level. Results: A total of 21 SVRF teeth involving 24 roots were analyzed in this study. Of them, 17 roots were complete fractures and 7 roots were incomplete fractures, resulting in a total of 41 fractures. SVRFs were more often found in roots of maxillary premolars and mesial roots of mandibular molars. All these roots exhibited buccal-palatal/lingual oval roots with two root canals. All fractures were in a buccal-lingual/palatal direction, affecting the middle region of the root and the root canal. There was no discernible pattern of fractures width either vertically or horizontally along the root. Conclusion: The SVRFs in endodontically treated tooth involve the middle region of the root, extending from the root canal to the root surface, and the crack width shows no obvious regularity. Therefore, we believe that the inner wall of the root canal in the middle region of root serves as the initial site for root fractures. The diverse and unpredictable fractures widths further highlight the intricate process of fractures development and expansion.

Key words: subtle vertical root fracture, fracture characteristics, micro-CT

LIU Wenjing, GAO Antian, PAN Xiao, CAO Dantong, LIN Zitong. Fracture Characteristics of Subtle Vertical Root Fracture in Endodontical Treated Tooth: An In Vitro Observation and Micro-CT Study[J]. Journal of Oral Science Research, 2024, 40(7): 617-621.

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