Department of Buccofacial Prostheses, University Complutense of Madrid, Madrid, Spain.
Int J Prosthodont. 2012 Jul-Aug;25(4):403-9.
The aim of this prospective study was to evaluate the clinical performance of zirconia-based posterior four-unit fixed dental prostheses (FDPs) after 4 years of clinical observation.
Between 2006 and 2010, 10 patients (5 women, 5 men; mean age: 52.8 years) received 17 posterior four-unit FDPs. Two calibrated examiners evaluated the FDPs independently 1 week (baseline), 6 months, and 1, 2, 3, and 4 years after placement using California Dental Association (CDA) criteria. Periodontal status was assessed on both the abutment and contralateral control teeth using Plaque Index, Gingival Index, probing attachment level, and Margin Index parameters. Statistical analysis was performed using descriptive statistics and the Wilcoxon signed-rank test.
Three restorations were lost because of fractures at their distal connectors after a mean clinical service of 25.3 months, and one abutment tooth was extracted because of vertical root fracture 23 months after cementation. Three FDPs presented chipping of a moderate size 1 week before framework fracture, and minor chipping was observed in 2 other FDPs 1 week and 36 months after cementation. After 4 years of clinical service, the cumulative survival rate of the posterior four-unit FDPs was 76.5%. No caries lesions were detected on the abutment teeth. The remaining restorations were judged to be satisfactory according to the CDA criteria. Periodontal parameters did not show significant differences between test and control teeth, but Gingival Index scores demonstrated a slight increase in inflammation in the distal abutments after 4 years (P = .016).
The use of zirconia-based posterior four-unit FDPs should be restricted for patients with high esthetic demands, except in patients where at least 4 mm of height is available for connector thickness.
本前瞻性研究旨在评估氧化锆基后牙四单位固定修复体（FDP）4 年临床观察后的临床性能。
2006 年至 2010 年期间，10 名患者（5 名女性，5 名男性；平均年龄：52.8 岁）共接受了 17 个后牙四单位 FDP。两名经过校准的检查者在放置后 1 周（基线）、6 个月以及 1、2、3 和 4 年，使用加州牙科协会（CDA）标准独立评估 FDP。使用菌斑指数、牙龈指数、探诊附着水平和边缘指数参数评估基牙和对侧对照牙的牙周状况。使用描述性统计和 Wilcoxon 符号秩检验进行统计分析。
3 个修复体在平均临床使用 25.3 个月后因远中连接体断裂而丢失，1 个基牙因垂直根折在粘固后 23 个月被拔除。3 个 FDP 在框架断裂前 1 周出现中度大小的崩瓷，另外 2 个 FDP 在粘固后 1 周和 36 个月出现轻微崩瓷。在 4 年临床服务后，后牙四单位 FDP 的累积存活率为 76.5%。基牙无龋损。根据 CDA 标准，其余修复体被认为是满意的。牙周参数在测试牙和对照牙之间没有显著差异，但牙龈指数在 4 年后在远中基牙的炎症略有增加（P =.016）。
除非基牙有至少 4mm 的高度用于连接体厚度，否则应将氧化锆基后牙四单位 FDP 的使用限制在有高美学要求的患者。
