PradeepKumar Angambakkam Rajasekaran, Shemesh Hagay, Chang Jeffrey Wen-Wei, Bhowmik Ahendita, Sibi Swamy, Gopikrishna Velayutham, Lakshmi-Narayanan Lakshmikanthanbharathi, Kishen Anil
Department of Conservative Dentistry and Endodontics, Thai Moogambigai Dental College and Hospital, Dr MGR Educational and Research Institute University, Chennai, India.
Department of Endodontology, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands.
J Endod. 2017 Jun;43(6):896-900. doi: 10.1016/j.joen.2017.01.026. Epub 2017 Apr 27.
This study evaluated the prevalence, location, and pattern of preexisting dentinal microcracks in roots of extracted teeth without endodontic treatment in patients from 2 age groups using micro-computed tomographic imaging.
Six hundred thirty-three nonendodontically treated teeth extracted using an atraumatic procedure because of reasons unrelated to this study were collected and divided based on the patient age. Teeth were scanned with micro-computed tomographic imaging (resolution of 26.7 μm) to examine the presence of preexisting dentinal microcracks in roots. The characteristic features of preexisting dentinal microcracks determined were location, extent, length, and coronoapical distribution. Chi-square bivariate analysis was performed to assess the association between various parameters.
Forty-five of 633 nonendodontically treated teeth exhibited preexisting microcracks in roots with a prevalence of 7.1%. The prevalence of preexisting microcracks was found to be 8.3% in older patients (40-70 years) compared with 3.7% in younger patients (20-39 years) (P < .050). A significant association was found between the preexisting microcracks in mandibular teeth (10.3%) when compared with maxillary teeth (2.9%) (P < .001). All preexisting microcracks were located mesiodistally; 66% occurred in the cervical and middle thirds of root. Only 33% of the preexisting microcracks were complete in nature, showing canal involvement. Complete dentinal microcracks exhibited a mean length of 6.9 mm, whereas incomplete cracks had a mean length of 3.75 mm (P < .001).
Preexisting dentinal microcracks in roots of nonendodontically treated teeth occurred more often in older patients (40-70 years) in the mesiodistal direction. They were predominantly found in the cervical and middle thirds of root and were more likely to be incomplete in nature.
本研究使用显微计算机断层扫描成像技术，评估了两个年龄组患者未经牙髓治疗的拔除牙根中已存在的牙本质微裂纹的患病率、位置和模式。
收集633颗因与本研究无关的原因采用无创方法拔除的未经牙髓治疗的牙齿，并根据患者年龄进行分组。用显微计算机断层扫描成像技术（分辨率为26.7μm）对牙齿进行扫描，以检查牙根中是否存在已有的牙本质微裂纹。确定的已存在牙本质微裂纹的特征包括位置、范围、长度和冠根分布。进行卡方双变量分析以评估各参数之间的关联。
633颗未经牙髓治疗的牙齿中有45颗牙根存在已有的微裂纹，患病率为7.1%。发现老年患者（40 - 70岁）中已有的微裂纹患病率为8.3%，而年轻患者（20 - 39岁）中为3.7%（P <.050）。与上颌牙（2.9%）相比，下颌牙中已有的微裂纹存在显著关联（10.3%）（P <.001）。所有已有的微裂纹均位于近远中方向；66%发生在牙根的颈部和中部三分之一处。仅33%已有的微裂纹在本质上是完整的，显示出根管受累。完整的牙本质微裂纹平均长度为6.9毫米，而不完整裂纹的平均长度为3.75毫米（P <.001）。
未经牙髓治疗的牙齿牙根中已有的牙本质微裂纹在老年患者（40 - 70岁）中更常发生，方向为近远中方向。它们主要位于牙根的颈部和中部三分之一处，并且在本质上更可能是不完整的。
