Thanks for posting your query.
It is good to know that you regularly visit your dentist
. Normally, this is how you know if there are any new cavities which needs to be taken care of. People don't visit a dentist unless they have a complaint like pain,bad breath
,etc. So regular dental visits are advised for every individual.I would advise you to do regular flossing too.Please don't neglect that.
Coming to your query, I understand that the hygienist noted an abscess
in your lower front teeth region in the gums. The change in the colour of your teeth shows that your tooth has become non vital. Non vital tooth, presence of abscess indicates that your front teeth had a history of a trauma. There is a possibility that you were hit on the front teeth, had a fall or some kind of injury
In this case, due to trauma, the pulp is injured and leads to non vital teeth. You don't get pain or sensitivity as the tooth is already dead or non vital. This in turn leads to abscess formation which is seen as a [black round] radiolucency in the xray. As your dentist correctly mentioned you need a root canal treatment
to treat this abscess. If the infection is too bad sometimes you may need an additional surgery which your dentist will take a call on. After the procedure you will need to crown the teeth.
Please continue with the prescribed medication and schedule your appointment for your root canal treatment with the dentist.I hope I have answered your question. If you have any more queries you can let me know.
Wishing you good health