At the beginning, what do dentists do?
not to make teeth white, or make teeth nice.
not to fill a tooth or to implant
but to end toothache.
A lot of people may feel scared both mentally and physically when talking about toothache. Why toothache is soooo painful?
First, pain is a signal delivered to the brain on nerve stimulation.
While toothache is a pain in pulp nerve, directly passed to the brain, so pain degree is far higher than skin trauma.

dental pulp is well protected by hard teeth shells. But it always gets sick inside the shell.
Once a tooth is decayed, or there is a hole in it, it can be filled with resin. Tooth is healthy again, and the process is easy. But if you igore it, the hole will go deeper, with bacteria and finally pulp infected. Even worse, teeth pulp may be exposed outside. At that time, you will feel toothache. The following treatment is much more complicated than have a filling.
Now dentists are all clear of how to cure toothache and do toothche precaution.
First, wipe out the rotten pulp to end toothache. Later, eliminate infection inside teeth. Finally block the way and thus bacteria have no chance to spread inside. That is called root canal treatment.

then how to do root canal treatment?
Step 1: local anesthetic is used and you have no feeling half the mouth. But actually many patients can stand the pain without anesthetic. Can you? Dig through the upper part of the tooth, have the pulp exposed and then wipe out all.
Step2: root canal preparation. This part takes a long time. It is very hard to operate. In fact, teeth pulp is similar to hair in thickness. Dentists will wipe out all inside as well as tooth pulp thoroughly with many speical tools. When this part done, your pain will be relieved.
Step3: After the wipe-out, the root canal is empty. Against infection, dentists will fill the canal with special gum. Have the canal fully sealed.
Step 4: Finally, patients always ignore the last part, yet it is very important. Through the treatment, you may feel better now. But actually tooth is more fragile than before, so it needs a crown to keep from bacterial infection.
Of course, if little part is missing in the tooth, there is no need for a crown. Resin can do a good job as well.