One of those days

[ASI]

Hi David,

Wow! Quite a series of events. Nothing that most of us have not seen before but certainly maybe not all at one appointment . That unit coming off the wall is a new one though. Better that than some overhead mounted equipment.

I feel your angst, David. Have a glass of wine and a good laugh.

Cheers,

Andrew

[dkimmel]

Andrew, It was just one of those days you just had to laugh at.
I was more concerned about giving up on the laser. This caries was old and tough stuff. I would guess the water content was ZIP. If I had an air abrasion unit it would not have been a problem. Heck if I even had Mark’s spoons it would not have been a problem. I started to give my head assistant a hard time about not having the spoons out of the autoclave, she then reminded me that she asked to order some more a couple of months ago.
Now it sure would be great if I did not have to put the high speed unit back in the op. If we could only polish with the laser!!

David

[Robert Gregg DDS]

Hey David,

Andrew’s right. That’s one to have glass of wine over……..would you like some cheese with that whine?:cheesy:

You know, with all our talk about the PerioLase for, well, perio, not a lot of discussion is made about its ability to remove that sort of decay using the short 100usec PD. Not a reason to buy one, in my opinion, but it would be there to assit in this sort of decay removal and clinical challenge.

Bob

[lookin4t]

I haven’t done a restoration excluding a small one on a relative in a long while….this made me laugh..with you.

[Swpmn]

Dave:

Funny story, I’ve got tons like:

When we set a patient’s bib on fire during an endo procedure; a giant Florida roach slowly crawled across the wall while I held an impression and the patient watched(the roach); lost a Peeso reamer in a female patients’ brassierre(found at the local hospital’s radiology unit); when the control unit on my fancy new electric handpiece blew up like a Fourth of July firework complete with smoke; or my all time favorite when I released a teenage girl from the operatory, she fainted in the hall and then her twin sister promptly fainted and collapsed right on top of her!!!!

But back to your findings, why is it that sometimes it seems that caries is the most difficult thing to remove with the erbium? Is that why slow speed burs and spoons are often recommended? Particulary on Class I and II lesions it seems at times I have difficulty with complete caries excavation. OR, do you think it really matters? Can we remove the majority of the caries, avoid a pulp exposure, properly bond the restoration and still be OK? I’ve changed my tune a bit lately and may be leaning toward the latter view.

Dr. Gregg’s point regarding the Nd:YAG is noteworthy. He once guided me on the removal of pigmented dentin lesions with the Periolase. Literally “pig-mented”;)

Anyone else having success using an Nd:YAG to excavate dark, pigmented carious lesions?

Al

[lookin4t]

Caries…yes, let’s see….I used to know what that was…

[Anonymous]

QUOTE

Quote: from Swpmn on 10:06 pm on July 5, 2004

But back to your findings, why is it that sometimes it seems that caries is the most difficult thing to remove with the erbium?  Is that why slow speed burs and spoons are often recommended?  Particulary on Class I and II lesions it seems at times I have difficulty with complete caries excavation.  OR, do you think it really matters?  Can we remove the majority of the caries, avoid a pulp exposure, properly bond the restoration and still be OK?  I’ve changed my tune a bit lately and may be leaning toward the latter view.

Dr. Gregg’s point regarding the Nd:YAG is noteworthy.  He once guided me on the removal of pigmented dentin lesions with the Periolase.  Literally “pig-mented”;)

Anyone else having success using an Nd:YAG to excavate dark, pigmented carious lesions?

Al

Great questions, Al.
Could it be that the  caries is more difficult to remove because the leathery or rubberlike caries absorbs some of the ‘explosion’ from vaporization and then you don’t get the same efficiency in ablation as you would with ‘hard’  enamel or dentin? You know, eric’s ‘for every action there is an  equal and opposite reaction’ ( enamel gives a harder wall to recoil against -just guessing, of course). I think the spoons and round burs are just a matter of convienence and speed.

As far as total caries removal, I think as Glass Ionomers become more popular there will be a change of thinking in this area, especially if ozone pans out.

Finally, I’ve never bothered to use my nd:YAG for the pigmented dentin lesions. Just too many other ways to do the same thing w/o using a second laser.

[Albodmd]

Dave,
I feel for ya man. Sorry to hear about your bad day. Hope your 4th was better.
Al B

[Swpmn]

QUOTE

Could it be that the  caries is more difficult to remove because the leathery or rubberlike caries absorbs some of the ‘explosion’ from vaporization and then you don’t get the same efficiency in ablation as you would with ‘hard’  enamel or dentin?  You know, eric’s ‘for every action there is an  equal and opposite reaction’ ( enamel gives a harder wall to recoil against -just guessing, of course). I think the spoons and round burs are just a matter of convienence and speed.

As far as total caries removal, I think as Glass Ionomers become more popular there will be a change of thinking in this area, especially if ozone pans out.

Finally, I’ve never bothered to use my nd:YAG for the pigmented dentin lesions. Just too many other ways to do the same thing w/o using a second laser.

Ron:

Thanks for your thoughts – that’s a good theory. Soft tissue is “soft” and wouldn’t provide much recoil either, yet it seems to ablate fairly efficiently with the erbium. Is that simply because it has a high water content?

Perhaps it’s not the caries itself that is difficult to remove with erbium but more related to depth and type of preparation. Particularly with the Class I we are shooting a laser beam into a “toilet bowl”, so maybe the irrigation water pools and absorbs most of the erbium energy? Maybe Dr. Gregg can help us here.

Are you using ozone therapy? I have some cases going on two years where not all caries was removed yet the patients are coming in for recalls without symptoms or clinical/radiographic findings. In many of these cases Vitrebond glass ionomer/resin has been placed over the incompletely excavated caries, others I’ve “self-etched” with Clearfil SE and then overlayed with flowable composite. Seems like I’ve heard there is some research showing it may not always be necessary to completely excavate caries.

Thanks for your input regarding the Periolase Nd:YAG for pigmented caries removal. Any thought on using an uninitiated, defocused 810-830 diode fiber not to remove but to disinfect or perhaps “carmelize” pigmented caries??

Al

[dkimmel]

I am not too keen on the idea of leaving caries behind. We are supposedly sterilizing it with the laser. I can live with that idea. Though I have a problem with deep of sterilization and caries at the CEJ. My big problem is bonding. Can you bond to caries? It like trying to bond to sclerotic dentin. You end up with a restortation that is bonded every place but at the caries which most often is the base of the prep.
As far as Glass ionmer— what a pain. I believe it works. The SEMs are impressive. I just have not seen any SEMs of Glass ionmer bonded to caries. My big concern is replacing a Glass ionomer restoration. My laser just does not like the stuff.

David

[Robert Gregg DDS]

Ron,

“Finally, I’ve never bothered to use my nd:YAG for the pigmented dentin lesions. Just too many other ways to do the same thing w/o using a second laser. “

Number of ways? Yes.

Quality of result? Hmmmm……

What about increased dentin bond strength post FRP Nd:YAG caries removal/dentin etch?

Bob

[Swpmn]

Dadgummit Bob, no response to my posts?

I thought Kimmel’s “Bad Day” presented us with an excellent opportunity for discussion??

Al

[Anonymous]

QUOTE

Quote: from Robert Gregg DDS on 11:07 pm on July 6, 2004

What about increased dentin bond strength post FRP Nd:YAG caries removal/dentin etch?

Bob

Is there something that shows a better bond than what’s obtained using an erbium to remove the smear layer after use of a spoon or round bur?

[Robert Gregg DDS]

Howdy Ron,

“Is there something that shows a better bond than what’s obtained using an erbium to remove the smear layer after use of a spoon or round bur?”

Yep, yep.  I think one is in your Day 2 book under “Laser Literature”.

Here’s one:

Effects of the pulsed fiberoptic-delivered Nd:YAG laser on dentin bonding

Joel M. White D.D.S., Harold E. Goodis D.D.S., Paul Khosrovi D.D.S., Chris M. Rose D.D.S.

Publication: Proc. SPIE Vol. 2672, p. 111-120, Lasers in Dentistry II; Harvey A. Wigdor D.D.S., John D. Featherstone, Joel M. White D.D.S., Joseph Neev; Eds.
Publication
Date: Apr 1996

Abstract
Laser modification of the dentin may increase the mechanical retention of composite resin restorations. The purpose of this study was to evaluate the effect of the Nd:YAG laser on dentin bonding. 170 dentin specimens were prepared by horizontal sectioning through the middle coronal third of molars. A 5 mm area of 140 samples were treated at powers of 0.3 to 3.0 W, pulse frequencies of 10 to 30 Hz, and energies of 30 to 150 mJ/pulse. The remaining 30 were untreated dentin sections. Samples were pumiced and bonded with Scotchbond 2 and Silux Plus composite, then light cured and stored at 100% humidity for 24 hours prior to debonding. Shear bond strength was measured and the type of failure was determined. Laser modification of the dentin improved bond strength by 68% compared with the controls. Microscopic examination of the lased samples after debonding showed that 5% failed adhesively at the dentin-resin interface, while 95% failed cohesively within the resin. Therefore, lasers increased dentin bond strengths by improving micromechanical retention.

There are others.

Since FRP Nd:YAG removes collagen and other organic components and causes the melting and resolidification of dentin–called “reactive dentin”–there is quite a clinical increase in bond strength and reduction in sensitivity due to closed dentinal tubules.

Bob

[Robert Gregg DDS]

Sorry Al,

I missed your post.  

“Perhaps it’s not the caries itself that is difficult to remove with erbium but more related to depth and type of preparation.  Particularly with the Class I we are shooting a laser beam into a “toilet bowl”, so maybe the irrigation water pools and absorbs most of the erbium energy?  Maybe Dr. Gregg can help us here.”

I think that is a good explanation.  FRP Nd:YAG works best on dry decay.  So when there is wet decay, we can use FRP Nd:YAG to dry it out and then it shrinks and shrivels–easy to spoon out, then use FRP Nd:YAG to etch and increase bond strength.

But FRP Nd:YAG is not any more efficient or faster, so I routinely use rotary instruments to remove wet and dry decay, THEN under magnification I use the Nd:YAG to remove the last remnants and etch

Thanks for your input regarding the Periolase Nd:YAG for pigmented caries removal.  Any thought on using an uninitiated, defocused 810-830 diode fiber not to remove but to disinfect or perhaps “carmelize” pigmented caries??

I wouldn’t to carmelize, but maybe to decontaminate and then do your indirect pulp cap technique to remineralize.  Since the last layer of “decay” is a bacteria-free zone, this explains why it works to not always remove all the decay, place Ca(OH)2, or lase, or SE and then bond.  I spoke to Prof. Harold Goodis at UCSF (a “pulpal biologist”) about doing this 12-13 years ago with FRP Nd:YAG and he said it should work like Ca(OH)2

“pig”-mented?  Like “de”-mented?;)

Bob

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