Teeth indentations are totally physiological.
If ulcerations are gone nothing to worry about as of now..
Do you feel dull diffuse pain in tongue?
Then there must be very prominent or sharp edged teeth cusps at lower back region on both sides.
In that case teeth need to undergo grinding to eliminate the sharpness of teeth edges.
Next Steps
visit dentist once in every 6-8 month for routine check up.
Health Tips
do not touch/bite your tongue involuntarily through the back teeth. do keep this in mind.
if your blood pressure is within normal limits, Luke warm water salt gargle can be done.
If BP is high, can use plain warm water for garggling few times a day.
maintain oral hygiene,
soft bristled brush. brushing twice daily, after food.
Tongue cleaning on regular basis
Use dental floss