hello and welcome to hcm forum,
i would like to inform you that a cut or abrasion on the gum tissue will heal on its own, do not apply any kind of tooth paste or ointment over it until prescribed by your dentist
is from the food particles which get stuck in there .
i will advise you to use an antibacterial mouth wash(twice/day),
avoid massaging the affected area until it heals completely.
If the tissue does'nt heal in 7 - 10 days then kindly see your dentist.
i wish you good health.