Which of the following restorative material is recommended for root surface caries?
Restorative Materials Used for Treatment of Root Caries

Direct filling gold was material of choice because of its ability to adapt the preparation walls with good marginal adaptation. But since isolation of these areas is difficult, the use of direct filling gold is decreased.
Dental amalgam is easy to manipulate, can be used in areas which are difficult to isolate and has self-sealing property. Traditional glass-ionomer cements have the desirable properties of being biocompatible, bonding chemically to tooth and showing anticariogenicity. But they have poor esthetics and excessive wear with time.
Resin-modified glass ionomers are biocompatible, bond to tooth, have thermal expansion and contraction characteristics that match tooth structure, and fluoride releasing feature.
Microfilled composites are recommended for root surface restorations as they have lower elastic modulus than hybrid composites. This is an advantageous property, since the teeth flex during mastication and a flexible material will be a better choice to restore the root surface.

Nisha Garg, Amit Garg. Textbook of Operative Dentistry.  Edition 3. Page: 68
GIC
Composites
Direct filling gold
Amalgam