<prompt> Classical monoblock in restorative and endodontic literature is:Primary monoblockSecondary monoblockTertiary monoblockQuartenary monoblock  <response>: The combined use of a core material and a cementsealer in contemporary endodontic obturations and fiber post adhesion introduces additional interfaces into a monoblock. Secondary monoblocks are those that have two circumferential interfaces, one between the cement and dentin, the other between the cement and the core material. A secondary monoblock is the type of monoblock that is classically perceived in the restorative and endodontic literature. 