This is achieved in a variety of ways, but essentially involves creating a raised groove or area along the posterior border, on the fitting surface. This is often referred to as the postdam.

这可以通过多种方式达到，但基本上不外乎，在基托组织面沿后缘制作一个突起的沟或区域，这就是常提到的后堤。

youdao

This is achieved in a variety of ways, but essentially involves creating a raised groove or area along the posterior border, on the fitting surface. This is often referred to as the postdam.

这可以通过多种方式达到，但基本上不外乎，在基托组织面沿后缘制作一个突起的沟或区域，这就是常提到的后堤。

youdao