*Bora Korkut, PhD, DDS, Department of Restorative Dentistry, Dentistry Faculty, Marmara University, Basibuyuk, Maltepe, Istanbul, Turkey.
Mutlu Özcan, PhD, DDS, Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, Center for Dental and Oral Medicine, Dental Materials Unit, University of Zurich, Zurich, Switzerland.
Oper Dent. 2022 Mar 1;47(2):138-148. doi: 10.2341/20-162-C.
To investigate the longevity of direct composites for Class IV restorations and the possible reasons of failure.
The longevity of 168 Class IV restorations in 50 adult patients was evaluated, in terms of modified United States Public Health Service criteria, for 4 years. Restorations were performed using a monochromatic layered microhybrid, resin-based composite (RBC) (Essentia, Universal Shade, GC Corporation, Japan; n=76) and polychromatic layered micro/nanohybrid (MD and LE shades, Essentia, GC Corporation, Japan; n=92) RBCs, by a single operator.
The majority of the teeth (n=156) remained acceptable at the end of 4 years, and the overall survival (OS) rate was considered as 92.86%. Survival rates for the monochromatic layering technique (MLT) and polychromatic layering technique (PLT) were 90.8% and 94.6%, respectively. Mean survival was 46 months for MLT and 47 months for PLT, indicating no significant difference (p=0.343). Fracture of the restoration was the most common reason for failure (4.2% out of 7.1% of general failures) for both the layering techniques.
Under the conditions of this mid-term clinical study, MLT and PLT as well as microhybrid and nanohybrid resin composite materials, showed similar clinical durability. In terms of simplicity, monochromatic layering can be preferred for Class IV restorations, when the right indication criteria are met.
研究 IV 类修复体直接复合树脂的使用寿命及其可能的失败原因。
对 50 名成年患者的 168 个 IV 类修复体进行了 4 年的随访，采用改良美国公共卫生服务标准评价其存活率。由一名医生使用单色调层微混合、树脂基复合材料（Essentia，Universal Shade，GC 公司，日本；n=76）和多色调层微/纳米混合（MD 和 LE 色调，Essentia，GC 公司，日本；n=92）进行修复。
4 年后，大多数牙齿（n=156）仍可接受，总体存活率（OS）为 92.86%。单色分层技术（MLT）和多色分层技术（PLT）的存活率分别为 90.8%和 94.6%。MLT 的平均存活时间为 46 个月，PLT 的平均存活时间为 47 个月，差异无统计学意义（p=0.343）。对于两种分层技术，修复体断裂是最常见的失败原因（7.1%的总失败中有 4.2%）。
在本中期临床研究条件下，MLT 和 PLT 以及微混合和纳米混合树脂复合材料具有相似的临床耐久性。在满足正确的适应证标准的情况下，单色分层技术在 IV 类修复体中可以优先考虑。
