Jacobsen I, Kerekes K
Scand J Dent Res. 1980 Oct;88(5):370-6. doi: 10.1111/j.1600-0722.1980.tb01241.x.
A follow-up study was made of 20 traumatized permanent incisors with pulp necrosis observed as a sequel to root fracture. The material included 19 patients aged 8-17 years (mean 11.6 years) at the time of injury. Negative response to electric stimulation was noted in 16 teeth from the first examination. In four teeth an initial positive response changed to negative within 2-9 months. The negative response was supported by additional signs and symptoms of necrosis in 19 teeth. Radiolucencies adjacent to the fracture line or coronal discolorations were the most important diagnostic factors. Discolorations occurred within 2 months, whereas radiographic changes in the fracture area took from 3 to 5 months to develop. Four teeth were extracted without attempting endodontic therapy. Endodontic treatment confined to the coronal fragment was performed in 16 teeth. In most cases the canal was filled temporarily with calcium hydroxide until a closure at the fracture site was observed. Two apical fragments showing radiographic changes were surgically removed in conjunction with the permanent filling of the coronal fragments. During the postoperative observation period one tooth was extracted due to communication between the fracture area and the oral cavity. The treatment of the remaining 15 teeth was judged as successful after a mean observation period of 4.2 years, ranging from 2 to 5 years.
对20颗因根折继发牙髓坏死的外伤性恒切牙进行了一项随访研究。该研究对象包括19名在受伤时年龄为8 - 17岁（平均11.6岁）的患者。首次检查时，16颗牙齿对电刺激无反应。4颗牙齿最初呈阳性反应，但在2 - 9个月内转变为阴性。19颗牙齿的阴性反应得到了坏死的其他体征和症状的支持。骨折线附近的透射区或冠部变色是最重要的诊断因素。变色在2个月内出现，而骨折区域的影像学变化则需要3至5个月才能显现。4颗牙齿未尝试根管治疗就被拔除。16颗牙齿进行了仅限于冠部碎片的根管治疗。在大多数情况下，根管先用氢氧化钙暂时充填，直到观察到骨折部位封闭。结合冠部碎片的永久充填，手术切除了2个显示影像学变化的根尖碎片。术后观察期间，1颗牙齿因骨折区域与口腔相通而被拔除。在平均4.2年（范围为2至5年）的观察期后，其余15颗牙齿的治疗被判定为成功。
