One of those days - Laser Dentistry Forum

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July 7, 2004 at 2:29 pm #6859 Reply

Robert Gregg DDS
Spectator

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

July 7, 2004 at 3:13 pm #6835 Reply

Anonymous
Guest

QUOTE

Quote: from Robert Gregg DDS on 10:13 am on July 7, 2004
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

Guess I wasn’t clear or am missing something. Has there been a comparison of bonding post erbium TX compared to bonding post nd:YAG Tx?

July 8, 2004 at 12:57 am #6864 Reply

Swpmn
Spectator

Interesting research I did not realize the Nd:YAG has been shown to increase resin bond strength to dentin. Did Joel and company etch the dentin with phosphoric acid in this study or were they only pumiced as implied in the abstract?

Al

July 8, 2004 at 1:32 am #6854 Reply

Albodmd
Spectator

Doesn’t Kanca advocate not removing every last bit of caries. If I remember correctly, didn’t he say the nutrients will be cut off to the remaining caries and they will arrest?

July 8, 2004 at 6:13 am #6848 Reply

lookin4t
Spectator

Yep…short post, but accurate

July 8, 2004 at 6:23 am #6855 Reply

Kenneth Luk
Spectator

Hi guys,

What about this PAD – PhotoActivated Disintection

There are 2 principal components:
PAD solution: A dilute solution containing pharmaceutical grade tolonium chloride
SaveDent laser: A low power 635 nm laser light source which optimally activates the solution through a disposable handpiece
PAD solution is activated by 635nm light and acts as a photosensitiser, releasing reactive oxygen species which disrupt the membrane of the micro organism. Independently, the laser and solution have no effect, but in combination produce a powerful anti-bacterial action.

http://www.defotex.com

Interesting?

Ken

July 8, 2004 at 2:32 pm #6857 Reply

Robert Gregg DDS
Spectator

Ron,

I am not aware of any head-to-head comparisons of Er:yag vs Nd:YAG.

My understanding of reading the literature and speaking to folks like Bryan Pope who has been using Er:YAG and Er:YSGG for a number of years is that both dentin and enamel “laser etch” are not clinically satisfactory. Bryan said he has seen a lot of microleakage at 2-3 years post placement of resins in both the enamel and the dentin erbium etched teeth.

On the other hand, FRP Nd:YAG has been extremely successful in real world private practice for me and Del for over 14 years. And the literature supports that w/o conflicting results by those who have investigated. Again, not so for erbiums.

Having said all that, there is a new study published in the ASLMS (Red) journal that I need to read in more detail.

Allen–I’m positive from speaking to Joel that he used P/A in the control.

Ken, that is interesting. It is the same idea that has been investigated for killing cancer cells (which has been met with mixed results), and the same as some folks are investigating for killing perio pathogens in the pocket–which I also think will be met with mixed and unpredictable results.

Why add a “foreign” substance to the already pigmented bacteria and when the is a device that is highly absorbed into those bacteria? Seems like more work, though the attraction is the potential to use a less expensive device in a diode versus short pulsed Nd:YAG.

When it is practical and convenient as well as “cheaper, faster, better”, then I will be even more inerested.

Bob

July 25, 2004 at 10:58 pm #6844 Reply

kellyjblodgettdmd
Spectator

Just got done reading this thread – brings up some great issues.

I think Dave has a good point to ponder – Should we use materials (i.e. glass ionomers) that aren’t cut well with lasers to restore teeth? I would like to give my two cents.

First, I don’t think dentin bonding with adhesive resins can hold a torch to using glass ionomers (i.e. Fuji IX) when replacing dentin. Sure you can bond to dentin with adhesive resins, but why? The hybrid layer created by the polyacrylic acid with calcium ions creates a far better seal than with resin. Also, consider that the average dentist probably doesn’t pay too much attention to C-factoring when placing composites.

Another question – Why are we concerned about how we will replace our restorations? If we consistently apply the CAMBRA principles with our patients, we shouldn’t have to worry about restoration replacement. It’s hard for caries to start when the bacteria have been squelched.

Since learning about the “Co-Cure” technique for placing hybrid glass ionomer/composite restorations, I have felt that this technique maximizes the advantages of both materials. After all, God built the tooth in two layers, too.

I realize this is more along the restorative line, than lasers. Sorry. I’d love to hear discussion, though.

Kelly

July 27, 2004 at 1:17 am #6839 Reply

dkimmel
Spectator

Kelly,
About ten years ago I would have agreed with you! Now that I have looked at my work 15 years latter, I am far humbler.
With the Co-cure technique and making CAMBRA part of our practices we should have less concern for replacing our restortations. Should is a key word!!! I really have no worries about using glass ionomers until I start getting into larger restorations. Anytime the marginal ridges are gone or the occlusal surface is >50% distroyed, I pause to think.
I think about parafunctional activities, diet and about the longevity of our materials. I also think about when I am projected to retire. I can retire in 30 Years. Would I be willing to bet the farm on the next 30 years having to redo one of these restorations? I used to really believe when I did a full mouth restorative case that it would last a life time. Since I am in Fl and most of my patients are in thier late 70’s , this was pretty safe. Well most are now in thier late 80’s and a bunch in the 90’s. I have had to eat humble pie a time or two.

I also think about when Panavia first came out. I was so good a few cemeted everything with it. Have you ever had to grind off a crown placed with panavia. If it was cemented correctly you GRIND it off.

When ever I treatment pllan a case I go back and try to decide where it will fail. At that point I either redisgn the case if I can or design the case so that it canbe salvaged in one manner or another. Using a Glass ionomer just makes thing more complicated in having to salvage a case. I say this but it is not a big deal. I would just pickup a highspeed. I still have one or two in the office someplace.

DAvid

July 27, 2004 at 1:34 am #6837 Reply

Anonymous
Guest

QUOTE

Quote: from kellyjblodgettdmd on 6:58 pm on July 25, 2004
It’s hard for caries to start when the bacteria have been squelched.

Kelly

Keeping them squelched is the hard part. I have far too many patients with less than ideal hygiene (or anything that even resembles that) to think I don’t have to worry about replacement someday. Like David, I plan and try to anticipate where that failure may occur. Sometimes I can help prevent it, sometimes I can’t.

What’s the estimate?- 1 marginal ridge gone, something like 37% loss of tooth strength. 2 ridges gone 88% loss of tooth strength ( I’m sure Graeme can give more exact numbers). So even though God built the tooth in two layers, I can’t come close to a equal replacement.

BTW, David you’re really must be much younger than I am if you’re practicing another 30 years [or is that when we pay off all the toys ;)]

August 2, 2004 at 1:44 pm #6842 Reply

kellyjblodgettdmd
Spectator

David and Ron. Good points. Certainly, one thing that you two have that I do not is more long-term clinical experience. Being that I’m only out of school for 5 yrs., I have not had the opportunity to see as much of my own work fail.

Another thought: One way I have found to minimize the disadvantages of posterior composites is using CEREC. If patients don’t want to afford porcelain, I’ll used the 3M Paradigm composite blocks. You can avoid all of the issues with polymerization shrinkage, build your anatomy as beautifully as you like, AND you can cut it out with the Er laser. It’s a hell of a lot easier than building up a posterior composite, especially when its large.

Thanks, guys, for accepting my lack of experience and not hammering me about it. Your both great professionals.

Kelly

August 2, 2004 at 10:00 pm #6851 Reply

2thlaser
Spectator

Ok, Kelly,
I’ll hammer you, your spelling of your should be you’re!

Hee hee.
Mark

August 2, 2004 at 10:25 pm #6845 Reply

kellyjblodgettdmd
Spectator

Yes, yes. My wife’s the one with the English minor!

What can I say – I’m a phonetical speller!

Kelly

August 3, 2004 at 12:09 am #6841 Reply

dkimmel
Spectator

Mark give him a break, he has only been out of school 5 years!!!!

August 4, 2004 at 12:31 pm #6850 Reply

whitertth
Spectator

5 I thought it was only 3!
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