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Greetings All,
I will post the pictures when I get to the office later today, as I had planned to do yesterday. Del and I have a lecture today and I’ll have some time to upload the images.
In the mean time, some may want to see the reaction I got on Dental Town while trying to show and share the technical applications for plused Nd:YAG.
Instead I got grief over the necessity of care–something I never tried to address in the first place.
Thanks to Ron Schalter who made a much appreciated supporting post and made my technical point–it was about what the 1064 laser could and couldn’t do.
And thanks to David Kimmel who hit the nail on the head (borrowing from “Doctor Ed’s” hammer analogy) when he also posted and made a very important point about aggresive carious lesions in the elderly due to medications, dry mouth, poor saliva flow, and the inability to detect carious invasion into dentin using radiographs.
The caries extended 3mm into dentin! Talk about being surprised! I was expecting the stain to blow out and be left with healthy enamel. It started out as a simple case of stain removal–one reason I didn’t charge the patient is because I didn’t prepare her for the fee in advance. Oops. But again, that wasn’t the point I was trying to make….I wasn’t trying to make a statement about these sorts of class I situations. There’s the Congress of Microdentistry, Kim Kutsch, Stu Rosenberg, and others to make that case.
Anyway, thanks or the support, guys, it’s greatly appreciated.
Now I know what Glenn van As means about the hostility to technology and his previous clinical posts on Dental Town!!! Geez, just trying to share technical capabilities and some differnt ways of solving clinical problems and some of those people get TWISTED about it!
http://www.dentaltown.com/idealbb/view.asp?sessionID={DC5AF088-EE75-477D-A1D6-81103B24213A}&topicID=16692″ target=”_blank”>http://www.dentaltown.com/gold….
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OK Gang,
Here’s the series if you haven’t already seen it. Better images here at Ron’s Forum and a more receptive audience. Sorry about the image sizes Ron–I’m still trying to make adjustments.
Pulsed Nd:YAG lasers are often thought of as ONLY “soft tissue” or periodontal lasers. However, pulsed Nd:YAG lasers have FDA clearance for hard tissue “indications for use”. One FDA clearance is for “enamel caries removal”. That is the removal of organic pigmented debris on and within the pits and fissures of Class I occlusal surfaces. The Nd:YAG 1064 nanometer wavelength is highly absorbed in chromatic pigments whereas this wavelength has very little effect on healthy enamel or water.
The high peak powers that a “free-running” pulsed laser (neodymium or erbium) can generate are powers on the order of 2000 to 3000 watts per pulse for one to two hundred MILLIONTHS of a second (microseconds) allowing the target tissue to reach it’s ablation threshold VERY rapidly resulting in rapid removal of the target substrate/pigment.
Pre-Op photo of the lower right second bicuspid on a 60 year old female with full compliment of teeth. Patient has stain and organic debris on the occlusal surface, as well as in the pits and fissures. To remove this debris with air abrasion, erbium laser or a diamond or fissurotomy bur before determining if there is decay present, could result in prepping a tooth that only has stain. Air slurry polishers might work nicely to remove the organic stain and reveal any remaining decay. However, having a laser that will selectively remove ONLY the organic stain or decay, and NOT any healthy enamel–and do so in microseconds–and before committing the patient and the tooth to a full resoration is a nice application if you indeed have such a device available.
Pulsed Nd:YAG at 100 microseconds (usec) Pulse Duration, at 3.00 watts of “average power”, 300 millijoules per pulse (mj/p), and 10 pulses per second (Hz) gives the operator 3000 watts per pulse. The stain and organic debris on the occlusal surface acts as an “initiator” or an activating pigment. Not unlike water does for erbium lasers. This was very interactive at this stage. No anesthesia was used. No “painting” of the tooth to create laser analgesia was used. No black suma ink “initiator” was used. No simultaneous water or air spray was used to cool the tooth. The patient was comfortable throughout.
Carbon deposits build up, even at short pulse durations, in the absence of water. Plasma and the ejected vaporized organic debris coat the tooth with a grey colored film. Water was sprayed on the tooth and the carbon was easily removed by lasing the discoloration THROUGH the water, obtaining absorption in the carbon, and preventing oxidation. This is a view into the occlusal pits and fissures.
Selective “photothermalysis” (a favorite term of my laser friend Geza) means I was able to remove the organic debris on and around the pits and fissures, but there is clearly more debris and/or decay present.
The inverted “V” pattern of decay once it hits dentin makes it necessary to remove enamel. The pulsed Nd:YAG will not do this. It will, however, remove decay and dentin if access is available.
So at this stage, the clinician can choose their own preference in accessing dentin and removing enamel–air abrasion, free-running pulsed erbium lasers, fissurotomy burs, etc.
In this case I used a flame diamond to open up the groove. Again, no anesthesia was used and the patient remained comfortable.
Enamel walls opened up, dentin and decay were accessed and removed with both the effect of the diamond and the use of the pulsed Nd:YAG.
Again, no anesthesia or any other effects were needed to remove decay or diseased dentin in this instance.
Tooth after etching with 37% Bisco phosphoric acid.
Bonding agent placed……..
Flowable composite placed, and polymerized with a pulsed Argon laser.
(One of the few contructive criticizms was about my use of a flowable composite. I agree, it is not the best choice for occlusal surfaces, since it is not highly filled. I simply was NOT planning on doing this for the patient as I thought it would only be a stain removal situation.)
Bob
(Edited by Robert Gregg at 10:31 pm on May 17, 2003)
Bob, the images here are much clearer than on DT. You can see the ‘hole’ started in the bi.
Just to be sure I understand, is the area circled in black (below) the area of carbonization (gray,dusty appearing)?
Thanks