Carbonates as Foaming Agent in Chip-based Aluminium Foam Precursor

Replacement of TiH2 as foaming agent by CaCO3（lime） and CaMg（CO3）2（dolomite） for AlMg4.5-and AlSi9Cu3-foams was investigated considering inluences on foaming capability and cellular structure.Precursor materials were produced from alloy chip and powder mixtures by means of the thixocasting process.AlSi9Cu3 variants showed expansion levels suffcient for commercial use.Variations in expansion observed when CaCO3 and CaMg（CO3）2 were compared as foaming agent are explained based on the course of decomposition.Improved performance of dolomite-based foams relies on formation of stabilizing MgO phases,which do not develop during decomposition of CaCO3 in Al-Si-Cu alloys

骨内牙种植体定位引导模板

应用种植定位模板对成功的种植修复是必不可少的。定位模板要制作简便，所包含的足够信息应能发挥准确的引导作用，包括种植体的数量、种植体的位置、种植体的方向以及所要求的种植体肩部的位置等。不同类型的模板应该能够适合于不同种植手术和固定及活动修复的需要。作者对目前临床上使用的各种种植定位模板进行了比较，以使种植修复体真正达到美观和功能性修复的目的。