Gold crown open margin! Help please

[nhitb]

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Hey guys!

So we are doing a project in indirect. We made a pindex and waxed up the tooth for the crown, invested then did casting. I seem to have 2 small spots where it shows as an open margin on the finish line on my crown.. they are very small but visible. This is only for a graded project.. is there any way i can fix this without having to redo it.?

 

[txaggie03]

back up several steps and make sure you're careful with your heat when you sprue and careful when you paint on the investment.

also, if you are not already, finish your waxup margins under a 10x microscope.

 

[TuckerT21]

Your first bit of advice was good, but a 10Xx microscope? That is so excessive.

 

[doc toothache]

Hard to imagine a ds where open margins would be acceptable.

 

[Mackchops]

Confirm you're seated - I assume you're checking the margins on your solid cast? Check your contacts and intaglio. If you used a high noble try pulling the margins closed. Otherwise sounds like you're hosed and may need to remake.

+100 on magnification! For waxing AND finishing.

 

[txaggie03]

Your first bit of advice was good, but a 10Xx microscope? That is so excessive.

You can call it excessive, but taking 3-5 min under a scope per crown and never having a margin problem speaks differently to me.

Throughout the entire process, I feel those minutes are the most important. There is no sense in casting it into a solid piece if you're not ready.

 

[OhioDMD]

Hey guys!

So we are doing a project in indirect. We made a pindex and waxed up the tooth for the crown, invested then did casting. I seem to have 2 small spots where it shows as an open margin on the finish line on my crown.. they are very small but visible. This is only for a graded project.. is there any way i can fix this without having to redo it.?

Kind of late to this party but if your margins are already knife edge in the open areas then the possibility of drawing down metal to close and cover the margin are nil. You may be able to close the open margin but you will be shy of the finish line. When/if you rewax and cast besides making sure you pattern is closed leave the margins heavy (thick) so that you can finish them with heatless stones and rubber wheels to a smooth knife-edge margin.