How do you protect front teeth white fillings from leaking?

Kteercute, that’s a good question.  Your not the only one to have this
concern.

 

Will those teeth need to be root canaled in the future due
to failed fillings?  The answer is
not necessarily.  Root canals are
needed because the tooth has “died”. 
This occurs due to either decay extending into the nerve or history of excessive
trauma.  So with fillings that are “leaking”,
if they are repaired or replaced before they get too big, then the likelihood
is, they will not require a root canal.

 

If there is a significant loss of tooth structure on the
back surface of the front teeth, like from GERD, and you are interested in
cosmetics for the front, then a full crown can be a better treatment choice.  Isn’t not ideal to have two separate
materials on a tooth when one can cover/apply both surfaces/materials.  If GERD is the concern, porcelain (from
a full crown) will last longer than a white filling.  I hope that was helpful.  

Provided your fillings were done well, and sealed properly, and protected from saliva at the time, they should last for 10-15 years.
After that time they are likely to start leaking a little. Modern light based scanners such as Soprocare will be able to spot that the leakage has started and allow your dentist to replace the fillings before they get deep enough to reach the root canals of the teeth. 
In terms of making them last longer?
Well the decay happens because you have sugar consuming bacteria on your teeth, and you feed them regularly. If you stop feeding them and clean all the plaque off, it is more likely they will fail-safe. That is, when they leak, they will eventually get loose then fall out, rather than decay happening and having a large chance of leaving you with a root canal. Seeing a hygienist every 6 months at least will also ensure that your hygiene is really as good as you think it is and further ensure that things fail-safe. 
Hope this helps and good luck.

Kind regards
Thomas Dey, BDS, MSc

Placing veneers is a great option however it is not a common practice to bond the back of the front teeth.