Modification areas

In the presence of a posterior modification space, a rest and a direct retainer placed on a secondary tooth other than the primary supports serves as an indirect retainer while also enhancing the retention, stabilization, and support of the prosthesis.

In a unilateral distal extension case with a posterior modification space, the primary abutments are the teeth adjacent to the distal extension denture base and the most posterior tooth on the dentate side of the dental arch. On the tooth-supported side, the rest anterior to the modification space serves as a secondary support, helping to stabilize the end of the tooth-supported segment and providing additional horizontal stability.

In the absence of a modification space, auxiliary occlusal rests and stabilizing components will be essential for cross-arch stabilization in the prosthetic treatment plan.