1. Can root canal infection always be treated successfully?

No, like any other procedure certain percentage could fail.

2. Are there alternative treatments for root canal? Should some people get a second opinion?

Second opinion can' t hurt, but if you trust your dentist no need for it. Removing the tooth in question is always an alternative to root canal therapy. Taking oral medication is just a short time solution and will not substitute the need for root canal therapy. 

3. Cavity becomes a root canal?

If a dental decay or cavity is left untreated it will evolve into a bigger problem affecting the very inside of the tooth resulting the need for root canal treatment. 

4. What is an abscess?

It is the name of an advanced stage of bacterial infection which could be the result of untreated dental problems or a complication of dental treatments. Pain, swelling, pus formation, bone loss, fever are few of the symptoms related to abscess. 

5. Does every abscessed tooth hurt?

No, not all the time. Dental infection could be a silent killer. It could destroy bone with no pain present. Luckily enough pain is present most of the time and forces the patient to seek help before it becomes a bigger problem.  

6. What happens when an infected dental pulp is not treated?

The problem will exist inside the tooth and will spread inside of the jaw bone creating infection around the tooth damaging the jaw bone. The infection could also spread further in the human body which could be life threatening, if left untreated.