Possible infection and treatment

[wariom]

Good morning,
I am 29 years old and I suspect I have an infection (without pain) at the root of tooth 31 that was devitalized 12 years ago.
When pushed back and forth with my fingers it has a slight mobility, I will not go into details of other health problems that
in my opinion are caused by this infection.
The dentist suggested a root canal retreatment.

My question is, if the root canal treatment was done perfectly the first time and then got infected, why should or
could it be curative the second time? In other words, it is not clear to me how the infection is treated and why even if it were treated
it should not then recur

Can anyone give me their very personal opinion on what is the best material to fill the canal with?
Is it possible to use silver instead of gutta-percha?
The priority is not to allow infections to form.

Thanks a lot to those who respond. Any advice is welcome

PS forgive my bad English, I'm Italian

 

[Dr M]

Firstly, this question is a bit loaded, since there is a lot of reasons why a root canal can fail. I always try and explain it to my patients like this- a root canal is the last treatment that we try, to keep the tooth in the mouth. All root canals don't last forever.
Gutta Purcha has been proven to adequately seal a canal, but it is also dependent on if the canal was properly disinfected prior to sealing it, and the amount of canals or accessory canals present, amongst a host of other factors.
A lot of times a lower incisor becomes re-infected, due to lateral accessory canals that was not disinfected adequately.
These canals are not visible on a conventional x-ray.
If the filling on top of the root canal, becomes deteriorated over time, there is also a chance that infection can leak into the canal from the top, leading to recurrent infection.
Luckily lower incisors are easy to re-treat.
If the infection does not clear, there might be micro fractures present and then the tooth might require an extraction instead.
If the infection does clear, I would advise placing a crown on the tooth.