This sounds like apexification or apexogenesis.
If the apex (tip of the root) is not yet closed it
can be stimulated to close with Calcium Hydroxide.
Generally this can take up to a year or longer.

CaOH also can prevent or treat external or internal
resorption which is rather common in traumatized teeth.

8 y.o. is rather young for a crown IMO.
To get maximum esthetics when a crown is
ultimately indicated I recommend an all ceramic crown.

Chromatec is the best looking IMO.

Hello all,

Our then 8 year old daughter, on a trip to a friends house last
winter, took a tumble on a trampoline and traumatized one of her upper
front teeth.  The dentist performed a root canal.  At the time, she
did not cap the tooth.  She informed us that at our daughter's age,
the canal was not ready for capping and we would have to wait while
the canal "closed" on its own.  She inserted some initial filler after
the root canal and on subsequent visits over the past year has
occassionally added more filler or just checked the status of the
canal with an x-ray.  According to the dentist, this is becoming
standard treatment for children's root canal therapy.

We are close to our one year anniversary of the event and are getting
a bit anxious about this treatment.  We've been told that the tooth is
more vulnerable until the crown is in place.  Our daughter is very
active in sports and we would like this to be resolved.

We would appreciate any insight from a dental professional or anyone
with a similar experience. Thanks.