Meijering A C, Creugers N H, Roeters F J, Mulder J
Department of Occlusal Reconstruction and Oral Function, Dental School, University of Nijmegen, The Netherlands.
J Dent. 1998 Sep;26(7):563-8. doi: 10.1016/s0300-5712(97)00032-8.
In this clinical trial, 180 veneer restorations (VRs) were evaluated. The purpose of the study was to collect survival data and to find possible relations between survival and (1) 'type of VR', (2) 'preparation design', (3) 'operator' and (4) the patient-related variables 'tooth-type' and 'vitality of the tooth'.
The restorations were provided by seven dentists in 1 12 patients on central and lateral maxillary incisors. Experimental variables were: 'type of VR' (either direct resin composite (DC), indirect resin composite (IC) or porcelain (P)), 'preparation design' (with and without incisal overlap) and 'operator'. Failures were recorded at two levels: absolute failure (need for new restoration) and relative failure (need for repair). Survival was defined at three levels: (1) survival of original restoration (Sr, endpoints: 'absolute' failures), (2) functional survival (Sf, endpoints: 'relative' failures) and (3) overall survival (SO, endpoints: both 'absolute-' and 'relative failures').
The variable 'type of VR' showed significant influence on Sf and So but not on Sr. Sf and So rates of P, IC and DC were, respectively: Sf-P, 94%; So-P, 94%; Sf-IC, 94%; So-IC, 90%; Sf-DC, 80%; So-DC, 74%. VRs on vital teeth showed a significantly better survival than VRs on non-vital teeth at all survival levels.
Preparation of the incisal edge for incisal coverage is considered to be unnecessary to assure or improve the strength of VRs. Veneers on non-vital teeth showed higher risk to fail than veneers placed on vital teeth. Porcelain veneers showed the best overall survival.
在本临床试验中，对180颗贴面修复体（VR）进行了评估。本研究的目的是收集生存数据，并找出存活率与以下因素之间的可能关系：（1）“VR类型”，（2）“预备设计”，（3）“操作者”，以及（4）与患者相关的变量“牙型”和“牙齿活力”。
修复体由7位牙医为112例患者的上颌中切牙和侧切牙提供。实验变量包括：“VR类型”（直接树脂复合材料（DC）、间接树脂复合材料（IC）或瓷（P））、“预备设计”（有或无切端重叠）和“操作者”。失败情况记录在两个层面：绝对失败（需要新的修复体）和相对失败（需要修复）。存活率定义为三个层面：（1）原始修复体的存活（Sr，终点：“绝对”失败），（2）功能存活（Sf，终点：“相对”失败），以及（3）总体存活（SO，终点：“绝对”和“相对”失败）。
“VR类型”变量对Sf和SO有显著影响，但对Sr没有影响。P、IC和DC的Sf和SO率分别为：Sf-P，94%；SO-P，94%；Sf-IC，94%；SO-IC，90%；Sf-DC，80%；SO-DC，74%。在所有存活水平上，活髓牙上的VR存活率显著高于无髓牙上的VR。
为保证或提高VR的强度，切端覆盖的切端边缘预备被认为是不必要的。无髓牙上的贴面比活髓牙上的贴面失败风险更高。瓷贴面显示出最佳的总体存活率。
