1. In this technique, the secondary impression is made
   after the construction of the metal framework and denture base. So, it is referred to as functional reline.
2. By using this technique, a new surface is added to the
   tissue side of the denture base.
3. This can be done before insertion or later if excessive resorption is present.
4. Procedure 
   1. A soft metal spacer (Ash No. 7 metal) is adapted over the ridge on the cast before the metal denture base is being processed.
   2. After processing, the metal is removed, which leaves an even space between the base and the edentulous ridge.
   3. Border molding is done and an impression is made using a low-fusing modeling plastic placed over the tissue surface of the denture base.
   4. The modeling plastic is tempered in a water bath and seated in the patient’s mouth until an accurate impression of the ridge is made.
   5. The patient should partially open his mouth during the entire procedure.
   6. After modeling plastic application is complete, about 1 mm of modeling plastic is scraped away uniformly from all over the crest of the ridge.
   7. The final impression is made with a free-flowing zinc oxide eugenol impression paste. In cases where excessive undercuts are present, elastomeric impression material is used.

Disadvantages 

1. Occlusion may be altered after the new denture base is processed.
2. Previous occlusal contacts cannot be established.
3. May be difficult to maintain the correct relationship between the framework and the abutment teeth during the impression procedure.