Gen Dent. 2021 May-Jun;69(3):37-41.
This in vitro study aimed to evaluate the influence of endodontic irrigation solutions and resin sealing of the dentin surfaces of the cavity before irrigation on the fracture strength (FS) of maxillary premolars. Seventy-two human maxillary premolars were randomly assigned to 6 groups (n = 12). Group 1 consisted of intact teeth that served as negative controls. In groups 2 to 6, root canal treatment was performed after mesio-occlusal preparation. In group 6, the dentin surfaces of the mesio-occlusal cavity were sealed with a self-adhesive flowable composite resin before instrumentation and irrigation of the canal. The volume and contact time of the irrigation solutions used during endodontic treatment of groups 2, 4, 5, and 6 were standardized as follows: 2 mL of 5.25% sodium hypochlorite (NaOCl) for 1 minute after each file, 5 mL of 17% ethylenediaminetetraacetic acid (EDTA) for 3 minutes after instrumentation was completed, and 5 mL of 5.25% NaOCl for 1 minute as the final irrigation. In group 3, the irrigation solution was normal saline solution only. After root canal obturation, in group 2, the cavities were left unrestored as a positive control. In groups 3 (saline-rinsed), 4 (conventionally restored), and 6 (presealed), the restorations were carried out with an etch-and-rinse adhesive and composite resin immediately after root canal obturations. In group 5 (delay-restored), the restorations were carried out with an etch-and-rinse adhesive and composite resin after a 1-week delay. After thermomechanical cycling, the teeth were subjected to FS testing under continuous compressive force. Data were analyzed with 1-way analysis of variance and Tukey tests. The unrestored group, which demonstrated the lowest FS, did not differ significantly from the conventionally restored group; the FS of both groups was significantly lower than that in the other groups (P ≤ 0.001). The presealed group exhibited the highest FS (P ≤ 0.02). The FS values of the saline and delay-restored groups were statistically comparable. In the present study, NaOCl/EDTA irrigation had an adverse effect on the FS. Presealing of the dentin surfaces of the cavity with self-adhesive flowable composite resin significantly increased the FS of aged composite resin-restored premolars.
本体外研究旨在评估根管冲洗液和在冲洗前对窝洞牙本质表面进行树脂密封对上颌前磨牙断裂强度（FS）的影响。将 72 个人上颌前磨牙随机分为 6 组（n = 12）。第 1 组为完整的牙齿，作为阴性对照。在第 2 至 6 组中，在进行近中-远中预备后进行根管治疗。在第 6 组中，在器械和冲洗根管之前，用自粘流动复合树脂密封近中-远中窝洞的牙本质表面。在根管治疗期间使用的冲洗液的体积和接触时间在第 2、4、5 和 6 组中标准化如下：每次换锉后用 2 毫升 5.25%次氯酸钠（NaOCl）冲洗 1 分钟，器械完成后用 5 毫升 17%乙二胺四乙酸（EDTA）冲洗 3 分钟，最后用 5 毫升 5.25%NaOCl 冲洗 1 分钟。在第 3 组中，冲洗液仅为生理盐水溶液。根管充填后，第 2 组不进行窝洞修复作为阳性对照。在第 3 组（盐水冲洗组）、第 4 组（常规修复组）和第 6 组（预密封组）中，根管充填后立即用酸蚀冲洗粘结剂和复合树脂进行修复。在第 5 组（延迟修复组）中，在 1 周后用酸蚀冲洗粘结剂和复合树脂进行修复。在热机械循环后，牙齿在连续压缩力下进行 FS 测试。使用单向方差分析和 Tukey 检验对数据进行分析。未修复组（FS 最低）与常规修复组无显著差异；两组的 FS 均明显低于其他组（P ≤ 0.001）。预密封组的 FS 最高（P ≤ 0.02）。盐水和延迟修复组的 FS 值具有统计学可比性。在本研究中，NaOCl/EDTA 冲洗对 FS 有不利影响。用自粘流动复合树脂对窝洞牙本质表面进行预密封显著提高了老化复合树脂修复前磨牙的 FS。
