Obviously I’m no physicist and am just beginning to understand a few things about dental lasers and tissue interactions. On the other hand, I’ve used a Er,Cr:YSGG dental laser system intraorally on humans for 2.5 years. Also, I’ve tested the laser on various materials and would like to add my observations to the discussion.

My Er,Cr:YSGG laser will ablate materials which contain or I believe contain varying amounts of water, e.g. hot dogs, gingiva, tongue depressor, enamel, dentin, caries, composite resin. The laser will not ablate materials which I believe contain no water, e.g. thin stainless steel matrix bands, gold(75%) crowns, feldspathic porcelain:

Pre-Test
[img]https://www.laserdentistryforum.com/attachments/upload/williamsa091803-1.JPG[/img]

Er,Cr:YSGG 20Hz 300mJoules 140usec PD 750-600umeter sapphire tip distilled water irrigant application time 60 seconds
[img]https://www.laserdentistryforum.com/attachments/upload/williamsa091803-2.JPG[/img]

Post-Test(note reflection indicating unbroken glaze)
[img]https://www.laserdentistryforum.com/attachments/upload/williamsa091803-3.JPG[/img]

If erbium energized water droplets were doing the ablating, would we not expect to be able to cut through a thin matrix band, cut into a gold crown(softer than enamel) or at least break the glaze on a porcelain crown?

Al

First:

Bob, thank you very much for your support. I take my science and research VERY seriously, and also question the “talking around my clear references and logic”.

I am also a BIG Trekkie, and remember clearly in 1979, Mr. Spock turning to Captain Kirk, when trying to disprove an impossible phenomena and saying, “Captain, even in this part of the galaxy, two plus two equals four”. Sometimes, truth is stranger than fiction.

Ray:

I will try to be brief.

Normal human (and dental pulp) temperature is 37 C. When radiant optical energy is applied to the oral tissues with a near infrared dental Erbium laser (Fried and many other studies), the temperature of the lazed area starts to rise immediately. In general, within biologic tissue each 10 C. rise in tissue temperature carries an injurious biological interaction with the tissue. At 45 C, the tissue becomes hypertherimic. At 50 C., there is reduction in cellular enzyme activity and some cell immobility. At 60 C, there is a denaturation of cellular proteins and collagen with the beginnings of coagulation. At 80 C, there is a permeabilization of cell membranes. And a t 100 C, there is vaporization of water and biological matter. If there is any significant duration of time that the temperature increase is at or beyond the 80 C mark (5 to 10 seconds), there will be irreversible and unwanted harm to the mucosa, bone, periodontal and or pulpal structures.

Now, that being said. Every one of the dentists on this board, with heavy water spray on the tooth, with a high-speed rotary instrument (dental drill) has “cooked a pulp or two in our time”. That means 100+C temperatures in the pulp for extended periods (by accident) with heavy water on the site as a heat sink to the friction we are creating.

In the Rizoiu et al paper that you seem to be fixated on, the temperature change discussed with a rotary instrument (dental drill) and NO WATER, was reported as a maximum of 14C as the bur perforated the pulp chamber. In a word, BULLSH-T.

If those were the kind of readings they were getting with the thermocouple they were using in the pulp chamber, in the face of Fried (with direct water access before crater formation) was getting 800C readings, I simply do not believe the Data.

Couple that to the “Non Existant” (not limited) “Non Existant” reliable references to the HK technique, and I simply discount this study to the bottom of my comic book pile.

That being said, take a look at another relevant study in the same journal from 2001.

Jayawardena et al, Pulpal Response to Exposure with Er:YAG Laser. Oral Surgery, Oral Medicine, Oral Pathology, Vol 91, No2, Feb 2001.

That is an excellent study from Japan with relevant histology, and in 26 references to Erbium lasers, not once, is any of Rizoiu’s work mentioned. Go figure.

Eric Bornstein DMD

Ray,

Now I understand why you talk in circles to the data Eric Bornstein presents.  You don’t recall, read or listen very carefully.  Then you are reckless in your conclusions and don’t have the self control to resist personal aspersions of others.

Here’s what I wrote in the paragraph just above what you quoted.  Go read it again.  The answer to your question is for all–even you–to read.

The statement I made was in reference to, and in description of, the animation that the quote appeared beneath.  That’s because the forum does not allow the animated GIF files, so I could only post it is a JPEG.  

You just didn’t look at the website and the animation, you saw that the animation showed water completely absorbing the erbium energy and being accelerated as one entire droplet mass to the target.  

To quote you again from your email to me on August 14th, “I have seen that vastly idealized version of “HK” before.  Not sure how to describe my impression of that Web site other than that I am glad that it is a dentist rather than Biolase hyping.”  

Your attempts to impugn my credibility is a transparent attempt to divert other people’s attention from the embarassing claims that you and the company you invest a great deal of money in are trying to protect and advance.

You can stand by anything you want, but your credibility with me is lost.

My apologies, once again, to Ron, Allen, and to the Forum.  I didn’t start this personalization.  Ray has reduced the conversations in this forum to personalization on two separate occassions.  I tried to end it once before in the Financial Forum discussion when he went off on me there for posting a business article.  I called Ray and told him I felt he was out-of-line to personalize a professional/business discussion.  

But Ray doesn’t seem to get it, or be big enough to stop it.  He appears from his most recent post, to want to take a “Guru” (his word) down a notch, since he thinks Gurus make posts w/o being questioned.  That appears to irritate him.  So instead of coming up with a professional reply (he’s not qualified, though) or coming up with someone who can match the expertise of the Guru he wants to challenge–he feels he needs to gets personal.  Well, I’m only going to put up with it for so long before calling BS on it.

Rays wants to shut me and Eric up.  Since he can’t do it with facts or science, he resorts to personal attacks.

Heck, Ray isn’t even a dentist.  He’s an investor, an money manager–a profiteer in our professional midst who’s motives are now pretty clear–discredit others he disagrees with.

Ray can’t quite punch through Eric’s scientific logic, but he hasn’t stop trying.  Next he tried to suggest that Eric doesn’t like research conducted by the company or its researchers.  But that’s not what Eric was saying.  But it was another attempt by Ray to find a personal bias in an argument he has lost.

I feel Ray owes me and the Forum an apology for twice now impugning the credibility of a Forum participant.  I’ve already made mine twice. But I’m not holding my breath.

I’ll be gone for the next 5 days to the AAP meeting in San Francisco…..where science takes a front seat and fantasy science and hype gets shown the door.

Robert H. Gregg, DDS  

To All:

Here’s the quote from the website with the animation.

“Demonstration of Biolase Waterlase cutting system combining laser energy with water droplets to create high-speed hydrokinetic water particles that can mechanically cut both hard and soft tissues.”

Here’s the link:

http://www.laser-dentist.org/laser.html

I’ll leave it to the Forum participants to decide if I accurately described the HKS effect as depicted in the animation.

Also, don’t forget to review the:  “**Facts documented by Biolase Technology, Inc. of San Clemente, CA.”  that are posted on the same page.

I am not making any statement regarding this particular doctor as I do not know him.

But this is exactly the point that Eric has been making–that unsuspecting doctors, who have little or no understandig of laser tissue interactions or laser physics that are being used in the  mid-infrared spectrum, and that only water is cutting.  That misunderstanding leads to false assumptions on the part of the clinician and then to the patient.

That is the concern I have over the exaggerated claims about the presumed mechanism being used in clinical situtions–patients can and do get hurt.

And company reps, investors, underwiters, executives don’t have to deal with the consequences of an injured patient.  They just move on to their next money opportunity.  The dental profession is left to deal with the fallout of the manufacturer’s greed.

Unless, of course, one recalls the malpractice lawsuits that Laser Endo Technic and their customer dentists were involved in!

If one does a Lexus-Nexus search for  Laser Endo Technic (Biolase predessesor company) one can still find the patient malpractice lawsuits and product liability lawsuits that Laser Endo Technic (now Biolase) paid hundreds of thousands of dollars in a judgements because of the reckless nature in which the company promoted the use of their Laser 35 for apicoectomies.  Sound familiar?

Laser 35 (and I have one) is a 35 Watt free-running pulsed Nd:YAG with an 800 microsecond pulse duration, fixed at 50 Hz only.

In testimony, one of the engineers said the device never should have been on the market.  Oops!  Guess tha FDA didn’t take a close look at that device and it mechanism of action either!

So sorry to the patient that you lost your maxillary anterior segment and all the teeth from Bicuspid to bicuspid.

And because it was a pulsed Nd:YAG–ALL pulsed Nd:YAGs have since been tainted by these lawsuits (there at least 2 that I followed).  And that was 10 years ago!

So don’t tell me that over-stated claims, exaggerated mechanisims of actions, dismissing scientific concerns doesn’t have consequences.

If you don’t have the studies to support your device and clinical use, then you are operating without science to support you in a clinical malpractice or peer review case.  And the investors and corporate profiteers won’t be around to lend a helping hand cuz they don’t care about your patients the way you do and must.  Just ask Laser Endo Technic….or whoever they are now.

Robert H. Gregg, DDS

Ray:

Here is a perfect “peer-review” study to further illucidate my point.

British Dental Journal
JUNE 24 2000, VOLUME 188, NO. 12, PAGE 680-686

“High and low torque handpieces: cutting dynamics, enamel cracking and tooth temperature”

T F Watson, D Flanagan and D G Stone

Objective: The aim of these experiments was to compare the cutting dynamics of high-speed high-torque (speed-increasing) and high-speed low-torque (air-turbine) handpieces and evaluate the effect of handpiece torque and bur type on sub-surface enamel cracking. Temperature changes were also recorded in teeth during cavity preparation with high and low torque handpieces with diamond and tungsten carbide (TC) burs.

This is directly from the discussion section of the paper:

“The final component of the study aimed to assess the effects on pulpal temperature of the different handpiece types. The recording of ‘pulpal’ temperatures using a thermocouple does not register the actual temperature generated by the bur at the cutting interface, but does give an indication of gross differences”

Now, this study (we are still debating) again is: “Pulpal thermal Responses to an erbium, chromium, YSGG Pulsed Laser Hydrokinetic system” by Rizoiu, Kimmel and Eversole, that was published in Oral Surgery, Oral Medicine and Oral Pathology in August of 1998.

Rizoiu et al, characterized thier infrared ablative “hydrokinetic” laser as not producing heat based on an intrapulpal thermocouple.

Clearly, from the Watson et al paper cited above, they stated that this method of assessing temperature does “not register the actual temperature generated by the bur at the cutting interface, but does give an indication of gross differences.”

Hence, that is why I characterised the Temperature data as Bullsh-t, because it is in no WAY, SHAPE, OR FORM, representative of what is happening at the Laser Tooth Interface, that they again describe as:

“On the basis of Phase Doppler partical analysis, Kimmel et al have proposed that the laser-target tissue interaction is dependent on a hydrokinetic tissue-cutting effect.

This once again is the Kimmel reference (from the Rizoiu et al paper) that I have NEVER been able to put my hands on, and never have I met or spoken to anyone that has ever seen it:

Kimmel AI, Rizoiu IM, Eversole LR, Phase doppler particle analysis of laser energized exploding water droplets. Abstracts of the International Laser Congress; Sept 1996; Athens, Greece, Abstract #67.

More double and triple speak that is far more confusing than convincing.

Do you now tip over your king sir?

Eric Bornstein DMD

Ray:

This is difficult to ascertain because the water spray only emanates from the handpiece when the laser is firing. Last weekend, Dr. Glenn van As prepared my mandibular canine for a composite resin restoration. My lower canines are worn due to my habit of tooth grinding as well as the fact that my maxillary arch is restored with abrasive porcelain restorations. Dr. van As approached my tooth in a “defocused” mode(10 mm) at which I noticed the sensation of cold. I would not describe the sensation as painful but simply unpleasant as if you walked from a 75 F room inside to a 45 F outside situation. When Dr. van As began preparation of my tooth, I did not experience anything different or anything I would describe as painful.

Al

Wow what a thread……and to think I am not even involved but I am sure glad that Eric and his wealth of science is here to dispute the Biolase HK claims.

Ray , I really dont understand why someone involved in financial aspects of a company cares one iota about HK.

It just makes no sense to me why you so feverishly defend the HK for Biolase but the more stock you acquire the more passionate it seems you become.

In closing I will say that I doubt any erbium laser can cut porcelain at all.

I suspect that the veneers that were cut were an indirect resin.

Prove me wrong someone please, show me a porcelain crown that is etched, show me a metal matrix strip that is etched, a gold crown, a silver amalgam……..oopss maybe we better not do that with certain lasers.

Oh but I must resist because that topic should fall under the maintenance section………

GRIN

I am just poking fun at everyone, so no need to get upset.

I will go back to my clinical findings, something which I know that I can do a little bit, and its great to hear Allen’s point of view on what it felt like. Thanks Allen, you were a GREAT patient.

My only claim is that with time the Biolase , Opus, Delight, Deka and Kavo will all be shown to work by similar mechanisms of action.

Oh ya Ray, one more tidbit for you.

I have been asked to provide and edit a chapter on erbiums for the next Dental Clinics of North America and I bet you a dollar you can guess how much enjoyment I am going to get in discussing the mechanism of action section……..

Gonna be fun fun fun.

Grin

Glenn