Kang Sung Hyun, Kim Bom Sahn, Kim Yemi
Department of Conservative Dentistry, Ewha Womans University School of Medicine, Seoul, Korea.
Department of Radiology, Ewha Womans University School of Medicine, Seoul, Korea.
J Endod. 2016 Apr;42(4):557-62. doi: 10.1016/j.joen.2016.01.014. Epub 2016 Mar 2.
The aims of this study were to analyze the distribution and characteristic features of cracked teeth and to evaluate the outcome of root canal treatments (RCTs) for cracked teeth. The prognostic factors for tooth survival were investigated.
Over the 5-year study period, 175 teeth were identified as having cracks. Data were collected regarding the patients' age, sex, tooth type, location and direction of cracks, probing depth, pulp vitality, type of restoration, cavity classification, opposing teeth, and previous endodontic treatment history. Cracked teeth were managed via various treatment methods, and the 2-year survival rate after RCT was analyzed using the Kaplan-Meier method in which significance was identified using the log-rank test. Possible prognostic factors were investigated using Cox multivariate proportional hazards modeling.
One hundred seventy-five teeth were diagnosed with cracks. Most of the patients were aged 50-60 years (32.0%) or over 60 (32.6%). The lower second molar was the most frequently (25.1%) affected tooth. Intact teeth (34.3%) or teeth with class I cavity restorations (32.0%) exhibited a higher incidence of cracks. The 2-year survival rate of 88 cracked teeth after RCT was 90.0%. A probing depth of more than 6 mm was a significant prognostic factor for the survival of cracked teeth restored via RCT. The survival rate of root-filled cracked teeth with a probing depth of more than 6 mm was 74.1%, which is significantly lower than that of teeth with probing depths of less than 6 mm (96.8%) (P = .003).
Cracks were commonly found in lower second molars and intact teeth. RCT was a reliable treatment for cracked teeth with a 2-year survival rate of 90.0%. Deep probing depths were found to be a significant clinical factor for the survival of cracked teeth treated with RCT.
本研究旨在分析牙隐裂的分布及特征，并评估牙隐裂根管治疗（RCT）的效果。研究了牙齿留存的预后因素。
在5年的研究期间，共识别出175颗有隐裂的牙齿。收集了患者的年龄、性别、牙位、隐裂的位置和方向、探诊深度、牙髓活力、修复类型、龋洞分类、对颌牙以及既往牙髓治疗史等数据。采用多种治疗方法处理牙隐裂，并使用Kaplan-Meier法分析RCT后2年的留存率，通过对数秩检验确定显著性。使用Cox多变量比例风险模型研究可能的预后因素。
175颗牙齿被诊断为有隐裂。大多数患者年龄在50 - 60岁（32.0%）或60岁以上（32.6%）。下颌第二磨牙是最常受累的牙齿（25.1%）。完整牙齿（34.3%）或I类洞修复的牙齿（32.0%）隐裂发生率较高。88颗牙隐裂经RCT治疗后2年留存率为90.0%。探诊深度超过6 mm是RCT修复牙隐裂留存的显著预后因素。探诊深度超过6 mm的根管充填牙隐裂留存率为74.1%，显著低于探诊深度小于6 mm的牙齿（96.8%）（P = .003）。
牙隐裂常见于下颌第二磨牙和完整牙齿。RCT是治疗牙隐裂的可靠方法，2年留存率为90.0%。发现探诊深度是RCT治疗牙隐裂留存的重要临床因素。
