Facing Walls in Dentin

[DarcyT]

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Facing walls in Dentin, internal or external walls?

 

[UConn_SDM]

Facing walls in Dentin, internal or external walls?

What?

 

[DarcyT]

What?

its part of retention form (internal shape that prevents filling from falling out) for a class II cavity prep (proximal box area). But i was wondering if the walls are considered internal or external.

 

[UConn_SDM]

Hmmm, sorry, I know all about retention and resistance form - I've never heard that terminology but maybe it's just me. Typically, I refer to these "facing walls" as the buccal and lingual axial walls.

As far as being internal or external? If you are talking about the buccal and lingual axial walls being "undercut" or convergent (for added retention form) as you look from the apical end of the tooth to the coronal end of the tooth, then these are internal as they are "within" the cavosurface margin of the prep.

More important is why do you ask?

[edit] also if we are talking about the same thing the facing walls are in dentin and enamel for a class II Ag.

 

[DarcyT]

Hmmm, sorry, I know all about retention and resistance form - I've never heard that terminology but maybe it's just me. Typically, I refer to these "facing walls" as the buccal and lingual axial walls.

As far as being internal or external? If you are talking about the buccal and lingual axial walls being "undercut" or convergent (for added retention form) as you look from the apical end of the tooth to the coronal end of the tooth, then these are internal as they are "within" the cavosurface margin of the prep.

More important is why do you ask?

Its an old test question on one of our exams. We have an exam in the morning and i was doing some last minute thinking. I was trying to figure out why it was an internal wall. I thought they (the walls) extended to the external tooth surface.

 

[UConn_SDM]

Not being familiar with this terminology......picture a class II Ag prep in your head. The cavosurface margin is where your prep (the hole you made) meets the intact exterior surface of the tooth. Everything in your hole is internal and everything outside your hole is external.

 

[toofache32]

internal

 

[adamlc18]

Dentin is an internal wall, i.e. it does not extend directly to the external surface.

 

[ItsGavinC]

What the heck, I'll throw my answer into the ring. Internal. 😀

 

[DarcyT]

What the heck, I'll throw my answer into the ring. Internal. 😀

We Didn't even have that question on the exam. But thanks anyway guys. I guess internal it is.