Preparing for a Root Canal: Know Before You Go To The Procedure (Part 2)

Now that you know what a root canal is, it’s important to know what to expect during your appointment.

During the appointment

During the appointment, your dentist will give you deep full local anesthesia, which is a little more than required for a filling because your dentist is removing the nerve.

Many x-rays will be taken to make sure that the instruments are in the correct location to remove the infected tissue.

Your dentist may place a sheet of latex, called a rubber dam, over your mouth, so that when the tooth is opened, no bacteria from the mouth can get in and when medications are used inside of the tooth, you don’t have an opportunity to swallow them. The rubber dam essentially isolates the tooth from the oral environment and in some cases helps the dentist do the root canal.

What to know for the appointment

The procedure should take longer than your standard filling. Expect to get very numb with local anesthesia.

Bring a book on tape or a long podcast you can listen to in order to pass the time.

One appointment vs. several

Some dentists will do a root canal all in one visit. Others will take two or three visits to do it.

Neither is better than the other — again, there are differing opinions on this. Some dentists wait and let the tooth dry and empty for a little bit and disinfect a second time then fill it.

I do all of my root canals in two visits because I think this is the best way to be as thorough as possible.

It’s more profitable to do a root canal in one visit. Doing a root canal in one visit might also be considered a service to you as the patient since it might be more convenient. But my recommendation is, be willing to take your time. Don’t rush it or try to speed things up because it is such a technique-sensitive procedure.

What to expect during the appointment

You shouldn’t have any pain. If the dentist is skilled at delivering the local anesthesia, you won’t feel a thing.

Sometimes, a dentist will begin the root canal and things go wrong — this can be a good thing! If your dentist gets inside the tooth and is presented with new information that changes the chances of success of a root canal, he will stop to tell you so you have the choice to abort the procedure before proceeding with a root canal that has lower chances of success than you both originally thought.

Reasons your Dr. may abort a root canal

A separated instrument: This is when an instrument breaks off inside the tooth.

A calcified canal: This is a canal that can’t be filled because you can’t get inside it. If the canal cannot be negotiated due to a calcification (this is actually the tooth trying to do its own root canal) then that means the canal cannot be properly filled, hence the prognosis of the root canaled tooth drops.

A fracture: Once the tooth is opened, your dentist might see a fracture which is not visible on the x-ray typically. A fracture makes a tooth have a poor prognosis even if your dentist does the perfect root canal because seepage can occur at the fracture line, which can lead to bone loss. If you lose bone around the tooth, you lose the support of the tooth. What I always tell patients in this situation is this: Don’t remodel the kitchen if you have dry rot in the floor! Abort the procedure in this case and go for an implant.

A curved root: Also called “complex canal morphology.” Canals bend and turn. Your dentist should only do the root canal if she knows she’ll be able to negotiate to the tip of the canal. If there is complex root canal anatomy — lots of twists and turns that are hard to navigate — then the chance of success of the root canal goes down.

Your dentist should only do the root canal if conditions are ideal.

You can drive home if you got just local anesthesia. If you got knocked out, you’ll need to be driven home.

What to ask afterwards

  • After the procedure, ask your dentist:
  • How difficult was it?
  • Was it easy to negotiate the canals?

Your dentist is required to tell you if anything went wrong during the procedure. Sometimes instruments will break off inside the canal — this is called a separated instrument (see above) — and your dentist is required to tell you about it. If your dentist doesn’t, the tooth will later become re-infected because you can’t seal past the separated instrument.

What to expect after you go home

You shouldn’t bite or chew on the treated tooth until you have had it restored with a crown by your dentist. A root canaled tooth is prone to fracture, so you’ll need to get the crown as soon as possible.

Until you’re able to come in to get the crown done, practice good oral hygiene and brush and floss normally.

Avoid biting on the tooth or chewing food on it.

Pain after a root canal

You might expect some pain, but don’t be surprised if there is no pain. No pain can happen and is not unusual.

If you do have pain, it usually peaks 17 to 24 hours after the procedure and it’s best to keep your head elevated while sleeping for the first one or two nights. If need be, take whatever pain medication that your dentist recommends.


Feeling soreness after a root canal is unusual, but it happens often enough to discuss. Your tooth can be sore and tender, but not necessarily painful, but sore and tender to percussion and chewing for up to six months, even after you’ve gotten the crown. the concept or theory here is that the infection was so great inside of the tooth that it affected the surrounding areas in the jaw bone and that the body has to fix those areas and that takes time.

Getting the crown

The sooner the better, because the tooth could cracker if you bite down on something hard. Once the root canal is done and pain has subsided, it’s wise to cover the tooth with a crown right away because a root canaled tooth has weakened and dried out. Covering the cored out tooth with a crown gives it virtually no chance of fracturing.

Some people wait to do the crown so that they don’t max out their insurance, but this can be a dangerous game. If the tooth breaks, you may lose your investment of the root canal and have to go to the implant and crown.

Be delicate with your tooth until you get the crown and try to stay off of it.