1. 半永久性：医疗填充物分为永久性(Permanent)及半永久性(Semipermanent). 永久性填充物包含众所熟知的矽胶、聚丙烯醯胺等化学聚合物;而半永久性有胶原蛋白、玻尿酸及多醣体聚合物,视不同的治疗目的而各有适用.
2. 半永久式：semipermanent packer 半永久型封隔器 | semipermanent 半永久式 | semipermeability 半渗透性
3. 渐渐消失的[辐射]损伤：radiolytic 辐射分解损伤 | semipermanent 渐渐消失的[辐射]损伤 | surfacc 地表塌陷(采矿)
adj
1. relating to or extending over a relatively long time
e.g. the long-run significance of the elections
the long-term reconstruction of countries damaged by the war
a long-term investment