00:00 Introduction
One area where we see a lot of confusion is with scan bodies for dental implants. And that's not a surprise, because they just aren't as straightforward as traditional impression copings.
00:18 Traditional impression workflow
When taking a traditional implant impression, you can use any impression coping that is compatible with that implant.
00:56 Why Scanbodies are different
Scan bodies are a different story. And that's because they're tied to the abutment manufacturer. For example, If you have a Straumann implant, and you use a Straumann scan body, we'll only be able to submit the abutment design to Straumann to manufacture the abutment.
In that same example, if you instead use an Atlantis scan body on that same Straumann implant, we would then have to submit the abutment design to Atlantis to manufacture the abutment.
01:26 But there is a way...
That being said, there is a way to have the abutment made by a different manufacturer than the scan body. To do that, we first have to print an analog model, and then rescan that model using the scan body of the preferred abutment manufacturer.
But, even though this does technically work, it's not the greatest solution because it comes at a cost of reduced accuracy. The reason for that is that we've now added two more steps that each introduce the potential for discrepancy.
01:55 Inaccuracies and their cause
With a typical intraoral scan case, there are four things that can decrease accuracy.
The first is the scan body itself. Depending on what it's made of, how many times it's been used and just overall how accurately it seats to the implant.
The second is the data acquisition. The type of intraoral scanner you're using and how proficient the employee is at taking the scan can both affect the outcome. Distortion can be just as common with an intraoral scan as with a traditional impression.
Third is the scan body alignment. This is where we match up your scan of the scan body to a library version in our software. The result of that alignment is rarely what we would consider perfect.
Finally is the fit of the analog in the model. And that's affected by the type of printer being used, the model material used, distortions from printing, fit tolerances where the analog gets seated, the type of analog, and how carefully the analog is placed in to the model.
Any of these things individually can affect the positional accuracy of the abutment and crown that we make. But since all of those steps are necessary, any discrepancy is compounded by another.
So, in a scenario where we have to print an analog model for rescanning, that additional scan body placement and scan body alignment just adds to that compounding effect and works to further decrease accuracy.
03:22 Labs don't accept all scanbodies
One final thing to keep in mind is that most labs don't accept all types of scan bodies. There are a few reasons for this, but one is that each type of scan body requires a different type of analog. So, if we accept 5 different types of scan bodies for a Nobel Conical Connection regular platform, we have to stock 5 different analogs to accommodate those. And that's just one platform. The total supply of analogs we have to keep quickly escalates when you factor in BioHorizons, Straumann, Astra, ZimVie and all of the other implant systems and sizes.
So, it's a good idea to check with your lab on which scan bodies they accept and which one you should use based on what they're going to make for you.
Alex Rugh, CDT
O'Brien Dental Lab
www.obriendentallab.com
