Tooth With Metal Filling Turning Blue?

"Tourism" dentistry as it is now called can save someone upfront costs but if something goes wrong you are up the creek without a paddle.  You can try and save money on things but dentistry is not one of them.  Pay a little more and stay where problems can be fixed.

Maxillary First molars statistically have the highest failure rate after endondontics of any tooth in the mouth. If a conventional root canal fails on the Mx first molar; I counsel my patients to extract the tooth, graft bone in the socket and then proceed with implant and restoration after 3-4...

Not sure how old your son is but if he has bumped a permanent front tooth then there is some trauma to the tooth from the initial trauma and again when he knocked off the bonding.  Seeing your dentist and letting them take a x-ray to check if their is a abcess is important...