Close or Dispose?

[nbrege]

I am using the following code to display a PDF file for a certain amount of time:

Dim p As New Process
p = Process.Start("acrord32", pdfFileString)
System.Threading.Thread.Sleep(3000)
p.CloseMainWindow()
p.Close()
'p.Dispose()  which one?

Should I use .Close or .Dispose after closing the process? What's the difference? They both say they release the resources associated with the process. Thanks...