It's just a fragment..go fr extraction of tooth pieces..d lump is due t infection..once u will get pieces extracted...it will go..

The term that we use for such decayed teeth is root stumps. There is no other treatment then extraction of these root stumps because they are damaged beyond repair. The lump on the gums that you see is called as a granuloma and is basically a reactive change by the body which can be removed along with the extraction procedure. The colour of the root stumps makes it very clear that the extent of decay is extensive, so it will be prudent that you do not delay the treatment until the symptoms aggravate further. Regards.