Could be.  You should be able to brush and floss the area and the gum
soreness should go away in a couple of days.  OTOH, sens. to hot and
cold can take some time to recover, esp. if the cavity was deep.  If the
sensitivity is prolonged (lasts more than a few seconds) or starts
spontaneously, or gets worse instead of better over time, return to your
dentist--the pulp of the tooth may be in trouble.

Steve