Hello, Welcome Thanks for consulting HCM,
I have gone through your query, as you have mentioned that you have gone to dentist
for cleaning your gums , dentist has given you injection , now you feel your ear clogged up , it can be numbess also thal you are feeling on your injection side, dont worry it can be due to nerve injury
You go to dentist again and disscuss your problem with them if it is nerve injury then take medication for it and if it is not due to injection then go to ENT surgeon
Hope this will help you.