Do there is any history of trauma? Please do mention.Some discolorations may be carcinogenic.

Please avoid using random home remedies for such conditions. Going by the description you have mentioned, it seems that the lesion is a melanocytic lesion, but the exact diagnosis will require a proper clinical examination and (if needed) a biopsy also. It would have been of some help if you would have posted a good quality clinical photograph along with your query. Some of these lesions might undergo spontaneous regression but that should not be expected in every case and more importantly, a visit to the dentist should not be delayed. Regards.