Bill wrote:
> On Jun 27, 9:58 am, churin <krone8...@mypacks.net> wrote:
>> I had metal crown on molar(#31)but it lasted about ten years. A part of
>> the top surface area was removed and cement underneath was exposed. The
>> broken crown was replaced with again a metal crown. This time it lasted
>> only one year. The damage was done in the same way as the previous one.
>> I chose metal crown because the both dentists who did the first one and
>> second one recommended metal crowns.
>>
>> I still keep the removed crown which lasted 10 years. It really looks
>> "worn out" and appears badly deformed from the original shape. It looks
>> as though the opposing porcelain bridge struck hard on the metal crown
>> which appears softer than porcelain so that it yielded to the impact by
>> deforming itself.
>>
>> Now I have to decide for a new replacement crown whether to go for metal
>> crown again or switch to porcelain.
>>
>> My question:
>>
>> What is typical life of a metal crown on molar?
>> What is a downside(s) of porcelain(PFM), cosmetic aspect aside?
>> Any suggestion for choosing type of crown?
>
> It sounds as though it might have been a cheap stainless steel crown.
> We call those "temporary."
>
> But even a cast metal crown (much better than stainless steel pre-
> formed) can eventually be worn through by harsh contact from an
> opposing porcelain bridge.
>
> Generally I like to make a crown of a material similar to that which
> it's going to occlude against (bite against).
>
> So if there are no other confounding factors, generally if the tooth
> is going to bite against a porcelain bridge, I like to place a
> porcelain crown to match.
>
> - dentaldoc
Is it true that if it is porcelain crown it may be prone to being
chipped by the opposing porcelain bridge or vice versa? If it is metal
crown it may be worn by the opposing porcelain bridge but if it lasts 20
years or more which my new dentist is telling me, then it is perfectly
acceptable.
BTW: There is one thing I left out from my original post. That is that
the crown was replaced actually for two times. The third one being the
present one is a porcelain crown. I notice there is a gap between the
crown and the adjacent tooth where food often stuck. If I attempt to
flos there the dental flos is easily cut off. My new dentist told me
that there is abbrasive edge on the crown which could be due to
chipping. I some times unknowingly crash sands while chewing food and
wonder if it caused damage to the crown.
Steven Fawks
Amatus Cremona
