If the reimported image does not appear in Lightroom, check that the Filmstrip Source Indicator and menu is not showing "Previous Import". If you have switched to "Previous Import", access the menu as shown and select All Photographs.
View samples in the Photomatix User Gallery.
Check the Photomatix FAQ for tips and other useful information.
If you haven't downloaded Photomatix Pro and its Plugin for Lightroom yet, you can do so from the download page.