Defective prosthetics?

[Helaury]

I had my two lower front teeth knocked out in the 1980s in teens. Prosthetics lasted into my 30s but had to have them glued back in place a couple of times.

In January 2013 they were replaced by new ceramic teeth. One fell off after a few month and was glued back. The second fell a few weeks later was glued back and fell again one or two months later (that's today).

Is this a symptom of a defect with the 'inlay cores'? Link:
s14.postimg.org/f6na9rgyp/100_1884.jpg

Also, the ceramic crown looks cracked along the edge. It shouldn't wear off so fast? Link:
s22.postimg.org/jjeu2rxsx/100_1885.jpg

What should I expect from the dentist who did this work?

PS: This was previously posted in the patient forum but it's going nowhere (and I don't know how to delete the original one) hence choosing to post in a specialty forum.

 

[Helaury]

According to the dentist who did the work, it's probably mechanical friction with the upper teeth that causes dislocation, which is a reasonable explanation. So he ground down the teeth' edges and glued it back in place.

 

[Helaury]

It just didn't work: the tooth is gone again. What could have gone wrong?

I don't want to be told 'let's just glue it back'. It's going to the fourth time. Please help.

 

[Helaury]

Overdue, but better late than never. The lesson from this and following appointments, is the teeth have to be filed down a bit. Repeated micro friction.