Nicholas Cobb, DDS

From your question, I am not sure if you are currently in braces or are already finished.

If you are in braces, sometimes gaps open up during movement and they will be closed later.

If you are finished with braces and gap opened then the retainer can be tightened to close this gap, or if it does not fit you can do a short invisalign case and close it.

The retainer itself would not be the cause for your tooth becoming uneven. There are usually two reasons:

1. the teeth have shifted and it appears uneven

2. wear during the day has caused you to chip or wear that tooth more than the others

It would not take long in an examination to determine what is going on and the correction is usually very minimal.

I would recommend that you use Invisalign to correct the spacing issues. Invisalign can now treat nearly all conditions that we used to use braces for. Most adults really prefer Inivsalign over braces because you will not see the wires and brackets.

Honestly almost 10 years is a decent time for the life of a crown. Many crowns last longer but even insurance companies will pay to replace a crown every 5-7 years. Sirona is the manufacturer of the machine that mills the crown they have no liability and do not provide the material for the crown. When a crown breaks it is usually only because of a few issues. First the dentist who placed the crown may not have provided adequate reduction to get the needed thickness for the material of the crown. This doesn't sound like it is the case because they would have failed much earlier than almost 10 years. The other issue is just normal wear and tear and habits of the patient. If you clench or grind your teeth you put more wear on the restoration. I see fractured natural teeth everyday, so if patients can fracture natural teeth they can definitely fracture a crown. CEREC is not too blame. When your new dentist places a crown there is a very good chance that the lab will be using a lab version of the CEREC machine to make your crown.

I would recommend titanium implants. They have been used for a very long time and have a great proven history. Zirconia implants just do not have the long term success behind them. Also, as for the abutment it really depends on the final shade of your teeth. If you have dark teeth then a titanium abutment will be okay. If you are going for a lighter shade then I would recommend a zirconia abutment with a titanium interface to the implant.