On 2006-08-11 12:23:13 +0100, Derek ^ said:

On Fri, 11 Aug 2006 12:09:15 +0100, Andy Hall
wrote:


They do fall off every couple of years, especially if a back tooth
that you chew on. No adhesive can stand the environment forever.

Hmm... Perhaps it's also a function of how much tooth surface is left.
I have 4 with no problems in 5-10 years.


My private dentist told me they are more secure if the sides of the
prep are nearer to parallel.

Makes sense.


He also said that the crown should be confluent with the root. To
achieve this the gums should be free from infection when the
impressions are taken since soft flabby swollen gums spoil the
impression.

This is one of the reasons that there is normally a delay after having
a root canal treatment before a crown is fitted. The other is that
the RCT might not work.

He also said my NHS crowns were "Atrocious".

Why am I not surprised about that?



DG