Forums › Laser Treatment Tips and Techniques › Hard Tissue Procedures › Question on Laser Etching
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drkddsSpectatorI’ve seen this topic in bits and pieces in other posts. I’d rather start a new thread rather than try to revive an old one.
I’ve read in some other posts that after laser etching, it is necessary to etch the enamel and dentin, especially dentin, to remove the ablation products. Visible by the change in color, disappearance of frost, in the dentin. Will this ablation product removal also occur with a self-etching adhesive? I never remember being told that a “smear layer” was produced by the Erbium laser. In fact, I was told just the opposite. Help….
sampat13421SpectatorI have limited knowledge about such things. However, I did once contact the makers of Clearfil SE, the bonding agent I use. Its a self etcher. They directed me to a study that indicated weaker bond strengths of their product if the enamel was “laser etched”.
I don’t recall what it said about dentine. I’ll attempt to contact the company again, as this is an important question. When I had asked the first time, it was before I had an Erbium laser, and perhaps didn’t pay as much attention as I should.
Sam Barr
sampat13421SpectatorI found one reference, but it talks about bond strengths to laser cut composite.
http://iadr.confex.com/iadr/2004Hawaii/techprogram/abstract_46005.htm
Sam Barr
kellyjblodgettdmdSpectatorDr. Graeme Milicich of New Zealand has been doing some great research recently regarding just this issue. He has been lasing teeth (enamel and dentin) and looking at the laser’s effect under SEM. The slides I have seen have shown some interesting effects. The bottom line, as far as I’ve been able to deduce, is that laser-ablated tooth can have a variably affected surface. This is greatly dependant on the power density at the time the energy contacts the tooth. If the power density is more than ideal, the result may be amorphous, aprismatic enamel which is not ideal to bond to. As a safeguard, it is probably wisest to scrape your prep with either a sharp spoon or round bur to unify the surface texture. Once this is done you can etch and bond.
As I understand it, this is more critical for the enamel surface. However, if the dentin has been lased, and hence there is no smear layer, it would probably not be adviseable to use a self-etching primer. As we know, the purpose of the self-etching primer was to get incorporated into the smear layer. But if there is no smear layer, this may not be the best choice.
Kelly
SwpmnSpectatorFor some clinical feedback:
In April 2002 we switched to Clearfil SE Bond for enamel/dentin conditioning after our erbium laser composite preparations. During this period, most of the margins were probably prepared at very high settings such as 20Hz 300mJoules. Later on, we began to reduce margin prep settings to 20Hz 150mJoules.
After some Continuing Ed in August 2003, we started mechanically planing our enamel margins with a spoon excavator to remove any friable enamel rods or products of erbium ablation left on the margins. Margins were generally prepped at 20 Hz 150mJoules or 10Hz 250 mJoules. Enamel/dentin likewise conditioned with Clearfil SE. This revised technique seemed to reduce our incidence of the “white line effect”.
Long term does it really make any difference? I don’t know. We don’t seem to see any trend where the first group of patients cycling through recalls require replacement of composites with defective or stained margins.
Al
drkddsSpectatorThis is very interesting.
When I saw Dr. Don Wilson last spring, he talked quite a bit about how the DELight (laser in general) didn’t produce a smear layer and hence 50% stronger bond, etc.
…and he said that he uses Prompt L-Pop exclusively.
Kelly, your post gives me a little different perspective on the self-etch BA. I’ve been an L-Pop user for almost 5 years. I’ve been in my current practice for almost 4 years and have seen few failures with L-Pop to date.
I’ve read some of the less-than glowing reviews on L-Pop, but it’s always worked well in my hands. Last fall I switched to Kanca’s Simplicity for a few months, but never felt comfortable with it. When I heard Dr. Wilson speak, I rejoiced and went back to L-Pop. This was unexpected…
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