<prompt> Which of the following should be done in case of unbounded amalgam restoration before application of copal varnish?Applied after removal of smear layer onlySmear layer left intactSmear layer is modifiedDentin desensitiser is applied  <response>: Sealing the underlying, prepared tooth structure is beneficial for any type of restoration. For an amalgam restoration, this can be accomplished without actually bonding the amalgam to the tooth. Nonbonded amalgams can have a sealed, prepared tooth structure through use of a sealer material such as Gluma Desensitizer or a cured resin adhesive placed before the amalgam insertion. 