Layton Danielle, Walton Terry
Faculty of Dentistry, University of Queensland, Australia.
Int J Prosthodont. 2007 Jul-Aug;20(4):389-96.
This study aimed to prospectively analyze the outcomes of 304 feldspathic porcelain veneers prepared by the same operator, in 100 patients, that were in situ for up to 16 years.
A total of 304 porcelain veneers on incisors, canines, and premolars in 100 patients completed by one prosthodontist between 1988 and 2003 were sequentially included. Preparations were designed with chamfer margins, incisal reduction, and palatal overlap. At least 80% of each preparation was in enamel. Feldspathic porcelain veneers from refractory dies were etched (hydrofluoric acid), silanated, and cemented (Vision 2, Mirage Dental Systems). Outcomes were expressed as percentages (success, survival, unknown, dead, repair, failure). The results were statistically analyzed using the chi-square test and Kaplan-Meier survival estimation. Statistical significance was set at P < .05.
The cumulative survival for veneers was 96% +/- 1% at 5 to 6 years, 93% +/- 2% at 10 to 11 years, 91% +/- 3% at 12 to 13 years, and 73% +/- 16% at 15 to 16 years. The marked drop in survival between 13 and 16 years was the result of the death of 1 patient and the low number of veneers in that period. The cumulative survival was greater when different statistical methods were employed. Sixteen veneers in 14 patients failed. Failed veneers were associated with esthetics (31%), mechanical complications (31%), periodontal support (12.5%), loss of retention >2 (12.5%), caries (6%), and tooth fracture (6%). Statistically significantly fewer veneers survived as the time in situ increased.
Feldspathic porcelain veneers, when bonded to enamel substrate, offer a predictable long-term restoration with a low failure rate. The statistical methods used to calculate the cumulative survival can markedly affect the apparent outcome and thus should be clearly defined in outcome studies.
本研究旨在对同一名操作者为100例患者制备的304颗长石质瓷贴面的效果进行前瞻性分析，这些瓷贴面已在原位使用长达16年。
纳入1988年至2003年间由一名修复医生完成的100例患者的304颗切牙、尖牙和前磨牙的瓷贴面。修复体设计有肩台边缘、切端磨除和腭侧覆盖。每个修复体至少80%位于牙釉质内。来自耐火代型的长石质瓷贴面经蚀刻（氢氟酸）、硅烷化处理后用粘结剂粘结（Vision 2，Mirage Dental Systems）。结果以百分比表示（成功、存留、未知、脱落、修复、失败）。采用卡方检验和Kaplan-Meier生存估计对结果进行统计学分析。设定统计学显著性水平为P < 0.05。
瓷贴面在5至6年时的累积存留率为96%±1%，10至11年时为93%±2%，12至13年时为91%±3%，15至16年时为73%±16%。13至16年期间存留率的显著下降是由于1例患者死亡以及该时期瓷贴面数量较少所致。采用不同统计方法时累积存留率更高。14例患者的16颗瓷贴面失败。失败的瓷贴面与美观问题（31%）、机械并发症（31%）、牙周支持（12.5%）、固位丧失>2（12.5%）、龋齿（6%）和牙齿折断（6%）有关。随着原位使用时间的增加，统计学上瓷贴面存留的数量显著减少。
长石质瓷贴面粘结于牙釉质基底时，可提供可预测的长期修复效果，失败率较低。用于计算累积存留率的统计方法可显著影响表面结果，因此在结果研究中应明确界定。
