Encke B S, Heydecke G, Wolkewitz M, Strub J R
Department of Prosthodontics, University Medical Center Freiburg, Germany.
J Oral Rehabil. 2009 Mar;36(3):226-35. doi: 10.1111/j.1365-2842.2008.01918.x. Epub 2008 Oct 22.
The aim of this randomized controlled clinical trial was to evaluate over a 5-year period, the clinical outcome of shrinkage-free ZrSiO(4)-ceramic (KaVo Everest HPC) full coverage crowns on posterior teeth in comparison with conventional gold crowns that served as the control. This study reports results of a 5-year study protocol up to 24 months. Patients totalling 224 were randomly divided into two treatment groups. Of these, 123 patients were restored with 123 Everest HPC crowns, fabricated by the Kavo Everest computer-aided manufacturing (CAM) procedure and 101 patients received 101 gold crowns, but two were excluded from analysis. All crowns were conventionally cemented with glass-ionomer cement. After an observation period of 6, 12 and 24 months, the prospective survival rates (Kaplan-Meier) for the KaVo Everest HPC crowns were 97.9%, 95.1% and 89.8% and for the gold crowns 100%, 94.8% and 92.7%, respectively. There were no significant differences between the two groups (P = 0.2). The 1-year failure rates were 4.9% for the KaVo Everest HPC crowns and 5.2% for the gold crowns. The 1-year cumulative risks for loss of vitality, secondary caries, fractures, loss of crown and extraction of abutment of the analyzed abutments (88) were 8.9%, 0%, 0%, 1.1% and 1.1%, respectively, for the gold crowns and 2.8%, 0%, 4.7%, 0% and 0.9%, respectively, for the ceramic crowns (107 analyzed abutments). No perfect marginal fit was shown by 49.5% of the evaluated ceramic crowns and 26.1% of the gold crowns. Only 1.9% of the KaVo Everest HPC crowns had a marginal crevice. In conclusion, Everest HPC crowns with an adequate occlusal tooth reduction of >1.5 mm are suitable for posterior restorations, but the marginal fit shows a potential for improvement.
这项随机对照临床试验的目的是在5年时间内，评估无收缩ZrSiO(4)陶瓷（卡瓦爱瑞思特高性能陶瓷）全冠修复后牙的临床效果，并与作为对照的传统金冠进行比较。本研究报告了一项为期5年、长达24个月的研究方案的结果。总共224名患者被随机分为两个治疗组。其中，123名患者用123个通过卡瓦爱瑞思特计算机辅助制造（CAM）程序制作的爱瑞思特高性能陶瓷全冠进行修复，101名患者接受了101个金冠修复，但有两名患者被排除在分析之外。所有全冠均采用玻璃离子水门汀常规粘固。在观察6个月、12个月和24个月后，卡瓦爱瑞思特高性能陶瓷全冠的预期生存率（Kaplan-Meier法）分别为97.9%、95.1%和89.8%，金冠的预期生存率分别为100%、94.8%和92.7%。两组之间无显著差异（P = 0.2）。卡瓦爱瑞思特高性能陶瓷全冠的1年失败率为4.9%，金冠的1年失败率为5.2%。分析的基牙（88颗）中，金冠的1年累计牙髓活力丧失、继发龋、骨折、冠脱落和基牙拔除风险分别为8.9%、0%、0%、1.1%和1.1%，陶瓷全冠（107颗分析基牙）的相应风险分别为2.8%、0%、4.7%、0%和0.9%。评估的陶瓷全冠中有49.5%、金冠中有26.1%未显示出完美的边缘密合度。卡瓦爱瑞思特高性能陶瓷全冠中只有1.9%存在边缘缝隙。总之，咬合面牙齿磨除量大于1.5 mm的爱瑞思特高性能陶瓷全冠适用于后牙修复，但边缘密合度仍有改进的潜力。
