根管治疗后下颌第一磨牙一壁型CAD/CAM高嵌体应力极限分析

Stress limit analysis of one-wall CAD/CAM onlays of mandibular first molars after root canal treatment

目的研究根管治疗后下颌第一磨牙一壁型计算机辅助设计/计算机辅助制造(CAD/CAM)高嵌体应力极限,为加快患者症状改善寻找有效方案。方法 25例根管治疗下颌第一磨牙缺损的患者,在接受根管治疗后,对患者实施为期3年的随访,详细了解患者的牙齿修复效果、应力变化情况、牙龈沟出血指数(SBI)、菌斑指数(PLI)及牙龈指数(GI)。结果患者修复后第1年的等效应力、第一主应力、第三主应力分别为(371.22±12.63)、(133.19±10.19)、(0.085±0.009)MPa,与修复后第3年的(370.56±10.19)、(131.56±9.58)、(0.084±0.003)MPa对比,差异无统计学意义(P>0.05)。修复后第1、3年,25例患者的牙齿稳固程度均良好,无脱落现象。修复后SBI、PLI、GI均高于修复前,但修复前与修复后SBI、PLI、GI对比,差异无统计学意义(P>0.05)。结论在下颌第一磨牙缺损治疗中,使用根管治疗方法能够取得理想的CAD/CAM高嵌体应力极限值,证明该方法可以提高患者牙齿性能,是一种科学有效的治疗方案。

Objective To study the stress limit of one-wall computer-aided design/computer-aided manufacturing(CAD/CAM) onlays of mandibular first molars after root canal treatment, and to find effective solutions for speeding up the improvement of patients’ symptoms. Methods 25 patients with root canal treatment of mandibular first molar defect. After receiving root canal treatment, they were followed up for 3 years to learn more about the patient’s tooth repair effect, stress changes, sulcus bleeding index(SBI), plaque index(PLI) and gingival index(GI). Results The equivalent stress, first principal stress, and third principal stress of the patient in the 1 st year after repair were(371.22±12.63),(133.19±10.19),(0.085±0.009) MPa, which had no statistically significant difference compared with(370.56±0.009),(131.56±9.58),(0.084±0.003) MPa in the 3 rd year after repair, and the difference was not statistically significant(P>0.05). In the 1 st and 3 rd years after repair, 25 patients had good teeth stability without falling out. The SBI, PLI, and GI after repair were higher than those before repair, but there was no statistically significant difference between SBI, PLI, and GI before repair and after repair(P>0.05). Conclusion In the treatment of mandibular first molar defects, the use of root canal therapy can achieve the ideal CAD/CAM onlay stress limit, which proves that this method can improve the patient’s tooth performance and is a scientific and effective treatment plan.