When you drop a cache binding for an object, all pages that are currently in memory are cleared from the cache.
sp_unbindcache to unbind a single entity from a cache.
sp_unbindcache_all to unbind all objects bound to a cache.
sp_unbindcache dbname [,[owner.]tablename [, indexname | "text only"] ]
sp_unbindcache pubs2, titles, titleidind
sp_unbindcache_all pubs_cache