Which of the following restoration is best for a tooth which is planned to be an abutment for RPD?
Removable Prosthodontic Abutment:
Teeth that are to serve as abutments for a removable partial denture can be restored with cast-metal restorations. The advantages of cast restorations are as follows: 

The superior physical properties of cast-metal alloys allow restorations to better withstand forces imparted by a partial denture.
Rest seats, guiding planes and other aspects of contour relating to partial dentures are better controlled when the indirect technique is used.

Sturdevant operative dentistry  7th Edition, Page No:e122
Amalgam restoration
Cast metal restoration
Glass ionomer cement
Composite restoration