Infected molar at bottom left jaw got two opinions from dentists. One said it is not salvagable and needs to extract. One said it can by doing a root canal and crown but he could not predict how long the tooth can stay. Don't know which advice i should
If it is a guarded tooth which it sounds like it is , you have to be ok with the idea that you will be dealing with this tooth again later and often times that means that the area around this tooth might have become more compromised and create a bigger problem. Since you are still questioning i would go to see an endodontist(a specialist who only does root canals) and see what he/she thinks the long term prognosis is.
If poor, i would advise taking out and consider an implant or bridge for tooth replacement.