Is the tooth or gumline swollen and or bleeding
is the gumline a different color or the cat have real smeely breath ( a
possible sign of an abcess)
 can you see the core of the tooth
is the cat pulling with his paw at his mouth
if yes to any of these go to the vet  or a vet dental car center

if not it is like us gettng a chipped tooth but pay attention to the cat no
matter what

http://www.fanciers.com/cat-faqs/health-care.shtml
Dental Care

Tartar buildup
Cats, like humans, have tartar buildup on their teeth called plaque. An
accumulation of plaque can lead to peridontal (gum) problems, and the
eventual loss of teeth. Plaque is a whitish-yellow deposit. Cats seem to
accumulate plaque primarily on the exterior face of their upper teeth.
Reddened gum lines can indicate irritation from plaque.
Some cats are more prone to plaque buildup than others. Some never need
dental care, others need to have their teeth cleaned at regular intervals.
Many vets encourage you to bring your cat in annually for teeth cleaning,
using a general anesthetic. The cost, which can be considerable, and the
risk of the anesthesia itself are both good incentives for doing some cat
dental care at home.
If you must have the vet clean your cat's teeth, see if your vet is willing
to try a mild sedative (rather than putting the cat under entirely) first
when cleaning the teeth. If your cat is an older cat (5 years or more) and
it must be put under, see if the vet will use a gas anesthesia rather than
an injected form.
What you can do:
Brush your cat's teeth once a week. Use little cat toothbrushes, or soft
child-size toothbrushes, and edible cat toothpaste (available at most vets
or pet stores). Cats often hate to have their teeth brushed, so you may have
to use a bathtowel straightjacket and a helper. If you are skilled and have
a compliant cat, you can clean its teeth using the same type of tool the
human dentist does.
Rootwork
Cavities in cat teeth often occur just at or under the gum line. If your cat
has an infected tooth, you will have to have root work done on it. It is
typical to do x-rays after such a procedure to ensure that all of the roots
have reabsorbed. If the roots haven't done so, then the infection can easily
continue on up to the sinus and nasal passages and from there to the lungs.
Such infections require long-term antibiotics.
Smelly breath
If your cat has smelly breath, there are various possible causes.
Teething: at about 6 months of age, cats will lose their baby teeth and get
permanent ones. If the gums are red and puffy and you can see the points of
teeth breaking through here and there, the cat is just teething and the odor
will subside as the teeth come in.
Gingivitus: if the gums appear red and puffy and you've ruled teething out,
your cat may have a gum infection of some sort. Take the cat to the vet.
Diet: certain foods, usually canned foods or prescription foods, can make
your cat's breath smell. If possible, try changing your cat's diet.
Abscessed tooth: may show no symptoms other than smelly breath. Drooling
sometimes occurs in conjunction. The cat must be taken to the vet to have
the abscess drained and possibly the teeth involved removed. If this is not
done, the infection can easily spread to the sinuses and cause the face to
swell, especially just under the eyes.

I would take the cat to the vet and have a complete exam done.
The first thing to look at in an injury like this is the
mechanism of injury.   If the tooth is chipped did other parts
sustain injury too?   That would be my prime concern and i'd
have the rest of the cat looked at to rule out any other
truama.    There may not be bleeding but there may be internal
damage that occurred along with the chipped tooth.

If you do not see the core of the tooth, no discoloring and the cat is not
in obvious pain there is not much can be done, but the cat does need to see
a
vet to verify these things.

Gina