Creating Spheres or Cylinders in 3ds Max will result in top and bottom vertex poles. A vertex pole is where multiple edges lead to a single vertex. This typically leads to a heavy triangle count around the pole that will not smooth well with the TurboSmooth or MeshSmooth modifiers. It also produces bad edge flow, making it difficult to select and loop or ring edges to make edits.
This tutorial will help avoid these problems and will allow you to produce quad topology spherical caps. The result of this tutorial can be seen in the first gallery image below. The other steps will take you through the process of creating the quad topology cap.