How to simplify the scanning workflow

May 23, 2017

Kenneth Magid, DDS explains how using a diode laser for digital impressioning can provide optimal results.

Digital impressioning is widely heralded for its accuracy, delivering far better results than utilizing conventional impressioning material. However, achieving those results can sometimes be tricky without a little extra help.

Kenneth Magid, DDS, of Advanced Dentistry of Westchester is an Associate Professor at NYU College of Dentistry teaching Honors Esthetics and laser dentistry. He explains how a diode laser is used to get optimal results for digital impressioning.

What is the benefit of incorporating a diode laser into your intraoral scanning workflow?

It’s essential, when you’re doing esthetic dentistry, to not only deal with the hard structure, the tooth structure, but that you also deal with the soft tissue, the gingiva and the contours of the gingiva, because that’s what will control the ultimate result of your esthetics.

If I’m going to control the esthetics, I’m going to need some way to alter the gingiva. That could be done with either a scalpel, an electrosurge or some form of laser. The disadvantage of the scalpel is that it’s going to bleed and then you can’t do almost anything afterwards, and it’s also very hard to make curved surfaces with a scalpel. You could use an electrosurge, but the problem is that it causes collateral thermal damage, or tissue destruction, far beyond where you cut. Almost a millimeter beyond what you remove is going to die back because of collateral thermal damage and you don’t want that.

So you want to use a laser. A diode laser, used properly – and especially the new BIOLASEEpic Pro – can be used such that it removes the tissue, it has almost no collateral thermal damage, no bleeding, no carbonization or tissue tags. From an esthetics standpoint, I can alter the tissue to create whatever shapes I want as long as I am in soft tissues.

Why use a diode laser for CAD/CAM and digital impressioning?

When you take any impression you must separate the tissue from the tooth structure, from the margin, in order to read the margin to create a restoration. With impression material, to an extent, that viscous impression material will sort of push the tissue away, and in some ways it can be forgiving. With CAD/CAM, you cannot have any place where the tissue is touching the preparation margin, because you’ll never be able to read the margin. That not only means the tissue as a whole, but it also means any tissue tags must not touch the tooth structure. When the scanner sees that the tissue is touching the margin, you will not be able to read the margin, and you will not be able to produce an adequate restoration.

So how do you move the tissue away from the tooth structure? You could use an electrosurge, which we used for years, and, again, the problem is you’ll get tissue die back way beyond where you want. Now this nice margin that you’ve got, right where you want it to be, it will be exposed, because the gum will recede there.

You could use cord, which means you have to pack one or two layers of cord under the gum. First of all, it is difficult and tedious. Second, if the preparation is at all subgingival, it really doesn’t work very well. With impression material, you can often get away with it – again, the impression material will displace the tissue, to some extent, because it has some viscosity. CAD/CAM doesn’t have that benefit. You can’t displace tissue, because there’s nothing to displace it. You must get the tissue away from the preparation. The best way of doing that is using a diode laser to remove just the inner surface of the tissue where it touches the tooth structure, giving you a crevice so that you can read perfectly with your CAD/CAM system.

The problem is the diode laser cuts with a hot tip. It’s the only laser in dentistry where laser energy is not doing the work. All the laser energy is doing is heating up the tip that you’re using, and it’s a hot tip that does the work. With most diode lasers, that heat is uncontrolled. You don’t know how hot that tip is getting. Also, the heat tends to vary dramatically, depending upon how fast you move through tissue and whether you are in air at all. That heat can vary enormously. If it varies too much, you can get collateral thermal damage or tissue destruction where you cut, which is what you don’t want.

The Epic Pro is the only laser in dentistry where we set the temperature of the tip exactly where we want it to be to do whatever work we’re doing. The tip feeds back the temperature to the laser device, and the temperature is kept at exactly that point no matter how fast or slow you cut, whether you’re in tissue or air or anything else.

What’s important, clinically, is what does it do? The advantage of the Epic Pro and the fact that we control the heat to your selected level, independent of how fast you move, independent of the tissue, is that you get that clean trough without carbonization and without tissue tags. This is essential for CAD/CAM.

Continue to page two to read about the benefits for labs, doctors and patients...

What are the overall benefits for labs, doctors and patients?

What the lab or the dentist who is designing and milling in his office gets, is a margin that is completely readable without tissue tags. The lab needs clear margins. They can guess at the margins – but they might be right or they might be wrong. When we’re doing a trough with the Epic Pro, the lab doing the restoration is getting a completely readable margin every time.

What the dentist gets is, A: The lab can read the margin, and B: when it comes back, because we don’t have tissue destruction beyond where we’re cutting, the dentist gets not only a restoration that fits the margin where it should be, but a tissue which comes right back to where it is supposed to be, originally, without the margin being exposed because we’ve overheated the tissue

What the patient gets is, first of all, there’s no discomfort from the procedure. No postoperative discomfort at all. And the patient gets a restoration that fits perfectly and tissue that is where it belongs.

What is the benefit of incorporating a diode laser into your intraoral scanning workflow?

Diode lasers are the most popular, but least understood, laser in dentistry. What dentists have routinely done is they’ve struggled to compensate for the deficiencies in the device. For example, with temperatures varying all over the place, and they’re getting carbonization or tagging or bleeding, and they’re using technique to overcome deficiencies in the device. What BIOLASE has done with the Epic Pro is have a device that does it for you, so you don’t have to overcome the deficiencies in the device.

When you cut tissue with a diode laser, you use an initiated tip. Most diode lasers are initiated by placing it in cork and firing the laser, or placing it on articulating paper, or some black medium, and firing the laser. The problem is it puts a layer of carbon that is really not part of the tip, and in fact, the minute you start entering tissue, within seconds, that carbon is wiped off. When it gets wiped off, we now have the laser energy, uncontrolled, going into the tissue, and the laser not cutting the way it’s supposed to. What we’ve done with the Epic Pro was develop tips that have a layer of titanium carbon oxide impregnated into the tip itself. You can cut far longer then anybody would continuously cut, but that initiation never alters, never wears off. So you get exactly what the device is supposed to do without compensating for it.