Check List for the Completed Maxillary Impression

The maxillary preliminary impression should be free of voids and provide detailed reproduction of all of the following:

• Maxillary tuberosities and pterygomaxillary notches
  
• Vestibules
  
• Hard palate including vibrating line
  
• Anterior soft palate
  
• Buccal and facial frena

No inner portion of the tray should be visible through the material.

Pouring the Preliminary Cast

Dental stone is mixed and flowed into the impression with the use of a vibrator, taking care not to incorporate air bubbles.

The Impression Base

Just prior to the final set of the stone, the cast is inverted onto a base. Extra material is removed. The model can be trimmed after the material is completely set.