If not finished or even if finished if not restored with a crown yes!

Yes. Teeth with root canals are dead teeth. They are made of 3-5 miles of microtubules that are now filled with bacteria releasing endotoxins and other microbes. There is no way it can truly be cleaned out. It now depends on the individual's immune system to constantly battle the bacterial invasion to the body. My advice is not to have a root canal done. A much safer option is to have the tooth removed, let it heal, and replace with a ceramic implant.

Hi,

Yes, you can. It could be due to a lot of reasons. I would recommend going to your dentist to get it evaluated. The following could be some of the reasons:

1) Not having a well sealed filling/crown on the tooth after the root canal to prevent the bacteria to leak into the tooth.
2) Reinfection of the tooth due to residual infection inside the tooth flaring up again.
3) Missed canal in the tooth while doing the root canal treatment.
4) Poor support to the tooth in the gums can lead to a gum infection.

There could be many other reasons. Depending on the prognosis of the tooth, it can be retreated with a root canal treatment or extracted and replaced with an implant/bridge.
Hope this helps. Stay safe and healthy.

If you think you have an infection, call the dentist, or endodontic specialist who provided your care. Slight sensation after a root canal is common. Swelling or severe pain would not be expected.

Yes. It is possible.

MDSDDS

Yes. There can be a recurrence of infection requiring further treatment.

Yes, you can have an infection in a root canal.
Thanks.