Abstract：
Treatment of a large proximal carious lesion that extends below the cementoenamel junction is challenging. Large defects usually require replacement with indirect restorations (inlays, onlays, or crowns). However, when the gingival cavity margins are deep, procedures such as isolation of the operative field, proper cavity preparation, successful impression-making, and adhesive luting may be hindered unless soft gingival or hard bony tissues are removed to expose the cavity margin. The present case report describes the clinical application of a conservative cervical margin relocation technique for treating deep cavity margins. A patient presented with large distal carious lesions and necrotic pulps in both the maxillary and mandibular right first molars, which were diagnosed with symptomatic apical periodontitis. After root canal treatment of both teeth, the maxillary molar underwent a crown-lengthening surgical procedure and subsequent placement of a zirconia crown. In the mandibular molar, the cervical margin was relocated by placing a composite resin base at the proximal gingival cavity margins under meticulous isolation of the operative field. The tooth was restored with a composite core build-up and bonded ceramic onlay. The satisfactory outcome suggested a promising prognosis for the oral health of the patient.
摘要：
在牙釉质交界处下方延伸的大型近端龋齿病变的治疗具有挑战性。大缺陷通常需要用间接修复(嵌体，onlays,或冠冕)。然而,当牙龈腔边缘很深，手术现场隔离等程序，适当的腔准备，成功的印象，除非去除软牙龈或硬骨组织以暴露空腔边缘，否则粘合剂可能会受到阻碍。本病例报告描述了保守的宫颈边缘重新定位技术在治疗深腔边缘的临床应用。一名患者在上颌和下颌右第一磨牙中均出现较大的远端龋齿病变和坏死牙髓，被诊断为有症状的根尖周炎。双牙根管治疗后，上颌磨牙接受了牙冠延长手术，随后放置了氧化锆牙冠。在下颌磨牙，在精心隔离手术区域的情况下，通过在近端牙龈腔边缘放置复合树脂基底来重新定位宫颈边缘。用复合核心构建和粘结的陶瓷嵌体修复了牙齿。令人满意的结果表明，患者的口腔健康预后良好。
