It depends on what you mean by "last".
If you mean how likely it is that the root canal treatment will have a successful long term outcome, then there are studies showing that root canal treatment in teeth with areas of bone loss around the root tips are about 70-80% successful over the long term. This is because teeth with this sort of radiographic appearance tend to have a much higher load of bacteria in the root canal spaces.
Other findings like internal or external root resorption (destruction of the root structure) or root fractures can compromise the strength of the tooth and the ability to seal the root canal system from bacteria.
If you mean how long the procedure time will be, it depends on whether both teeth are to be treated in the same session, if the root canal treatment is to be completed in a single visit or multiple visits, how experienced the operator is, if the operator is using magnification and if there are any complications during the procedure.
