Dental PFM Crown White Gold Dental Post and Core ISO13485
Teeth sometimes have large portions missing due to decay, fracture,
the loss of a filling or the creation of an access cavity(the hole through which root canal work is performed).
Core placement refers to a procedure where a dentist replaces the
bulk of a tooth's missing structure in preparation for making a new
dental crown. Doing so creates the optimal shape and foundation for
the new restoration.
What materials are used?
A core can be made out of any type of permanent dental restorative.
In most cases it's either:
1) Dental amalgam (the metal used to make "silver" fillings) or
2) Dental composite (the dental bonding used to make "white"
A core replaces lost tooth structure that's needed for crown
Why is a core needed?
A great deal of a crown's stability depends on the amount of tooth
structure that extends up into its interior. If very little tooth
structure fills this space, the crown will be easily dislodged,
especially by forces directed from the side.
What a core does.
By "building up" the tooth first with a core (rebuilding the tooth
so it is closer to its original dimensions), the dentist can
greatly increase the stability of the crown, and therefore maximize
its long-term chances for survival.
What is a "post and core"?
The difference between a dental core and a post and core is that
with the latter, a dental post is placed that helps to anchor the
core to the tooth.
While a dental core can be created for any tooth, a post and core
can only be made for a tooth that has had root canal treatment.
X-ray of tooth that has a post & core and dental crown.
The post is positioned in the tooth's root. It's attached core
extends up inside the tooth's crown.
Is a post always needed?
As general rules of thumb:
- If more than half of a tooth's original crown portion (the part of
the tooth normally visible above the gum line) has been lost, a
post is needed to assist with anchoring the core to the tooth.
- If more than half of the tooth's crown still remains, a core by
itself will probably suffice.
Posts don't strengthen teeth.
In decades past there was a misconception that metallic dental
posts played a role in reinforcing (strengthening) the teeth in
which they were placed.
To the contrary, dental research has since shown that these posts
offer no reinforcement benefit and, in fact, can actually weaken
teeth and place them at risk for fracture. (Raedel 2015)
Heydecke (2001) reported that case failures not involving
situations where a post had been placed were more likely to be
"repairable" (procedures could be performed where the damaged tooth
could still be salvaged).
As evidence of this we'll mention a study by Willershausen (2005)
which evaluated 775 endodontically treated (root canalled) teeth.
- It was determined that as a group these teeth had a complication
rate of 6.6%. (This included events such as root fracture.)
- In comparison, a subgroup composed of just those teeth having metal
posts had a complication rate of 13.2% (twice as high).
These findings aren't meant to suggest that post placement is a
"bad thing." However, a dental post should be recognized as just an
aid in helping to anchor a dental core to its tooth. If enough
natural tooth structure still exists, then no post is needed and
for good reason should not be placed.