Bentley C, Drake C W
J Dent Educ. 1986 Oct;50(10):594-600.
The longevity of 1,207 restorations placed by students was studied in 70 adult patients. The overall percentage of restorations lasting ten years or more (P10) was 75.4 percent and survival times were longer than in most previous restoration longevity studies. Cast restorations lasted significantly longer than amalgams, which in turn lasted significantly longer than composites. P10 values were 91.1 percent, 72.0 percent, and 55.9 percent, respectively. Analysis by surfaces involved indicated that single-surface lasted longer than multisurface restorations. The survival of restorations placed in patients aged 60 or more was less favorable (P10 = 56.8 percent) than for younger patients (P10 = 78.3 percent). A subset of the population was identified on the basis of a restoration failure rate of greater than 4.0 X 10(-2) failures/restoration year. This group, comprising 18.6 percent of the population, accounted for 56.1 percent of all restoration failures. The P10 value for this high-risk group was 55.8 percent, as compared with 83.9 percent for the remainder of the population.
对70名成年患者中由学生放置的1207颗修复体的使用寿命进行了研究。使用十年或更长时间的修复体的总体百分比（P10）为75.4%，并且其存活时间比以往大多数修复体使用寿命研究中的要长。铸造修复体的使用寿命明显长于汞合金修复体，而汞合金修复体的使用寿命又明显长于复合树脂修复体。P10值分别为91.1%、72.0%和55.9%。按所涉及的表面进行分析表明，单面修复体的使用寿命长于多面修复体。在60岁及以上患者中放置的修复体的留存情况（P10 = 56.8%）不如年轻患者（P10 = 78.3%）。根据修复体失败率大于4.0×10⁻²次失败/修复体·年确定了一部分人群。该组占总人群的18.6%，却占所有修复体失败的56.1%。该高风险组的P10值为55.8%，而其余人群的P10值为83.9%。
