You guys still bumping chests over this? Here is one just to stir the pot more for fun.

A more confined approached to energized water ablation induced by laser. Research conducted at:

<a href="http://ceres.ifs.tohoku.ac.jp/~swrc/

Application” target=”_blank”>http://ceres.ifs.tohoku.ac.jp/~swrc/

Application of laser-induced liquid jet and shock waves to medicine
Makoto Komatsu
Water vapor bubble is produced by energy absorption of water. And large energy supply for a extraordinary short time brings about formation of underwater shock waves. Energy source for these phenomena is laser emission, electric discharge, explosive and so on.
In SWRC, production of bubble and shock waves in water with laser irradiation has been studied. Laser which has wavelength close to light absorption spectrum of water have to be employed as effective energy source. Holmium YAG (Ho:YAG) laser beam has 2.1 ƒÝm wavelength, which is close to 1.9 ƒÝm of a light absorption spectrum of water. Therefore, Ho:YAG laser is suitable to generate bubbles and shock waves in materials including a large amount of water.
Living body has large including ration of water. Hence, behavior of bubbles and shock waves in living body is similar to that in water. Based on these backgrounds, development of medical technique with laser-induced liquid jet and shock waves has been conducted for application of this novel to medicine.
Laser-induced jet is produced by laser emission in narrow capillary tube. Fig. 1 explains the process of laser-induced liquid jet production. Optical fiber is inserted into a capillary tube filled with water. Laser beam transmitted via the fiber produces water vapor bubble growing toward the capillary exit, and then water is expelled from the exit by expanding bubble. Water flow generated by the emanation of water produces liquid jet finally. Development of fibrinolytic treatment for cerebral arteries and surgical knives with the laser-induced liquid jet has been performed with Department of Neurosurgery, Tohoku University Graduate School of Medicine.

Bob, the Kodak patent does not specify the phenomena as being unique to any wavelength in particular although they did refer specifically to Biolase’s patent and Er,Cr:YSSG for its high water absorbance and used it in their experiments. If your question is about the Japanese work, I am not sure why the SWRC folks chose Ho:YAG for their experimental setup. Could be finances – you know how research gets funded in grad schools. I am surprised that their apparatus worked as well as it did using a lousy wavelength. Makes me wonder what the apparatus could have done with an Er source.

Hi Ray,

We have an awesome scanner. What’s it worth to ya?

Give me another chance too, to show you photoacoustics with FR Nd:YAG……..;)

Bob

Hey Bob,

But my scanner has got HK and it still doesn’t do the figures well enough.

HK = hong kong

Al: Thanks. Does Dr Fried et al monitor the discussions. If so, I would surely like to ask him some specific questions about his paper(s).

This is from the Biolase web site.

What are benefits of the Waterlase™ ?

•Waterlase™ uses a cool-water spray to cut teeth without generating heat. Conventional drills and lasers can overheat teeth during procedures, inducing discomfort and irreversibly damaging the soft tissue or pulp underneath.

How does Waterlase™ work?

•The Waterlase™ system uses laser-energized water to cut teeth.

•The Waterlase™ emits a laser beam that energizes a highly precise spray of air and water.

Water droplets absorb the laser energy and become laser-energized water particles that, when directed at the tooth, rapidly remove enamel, dentin and decay/caries.

Now, before one deals with the question of hydrokinetics, one must first deal with two laws of physics that at this point in our history should be irrefutable.

1) Newton’s third law of Motion:

Newton states that whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first. In other words, to every action there is always opposed an equal reaction. Neither force exists without the other, and forces come in pairs. The action and reaction pair of forces makes up one interaction between two things.

Now, lets extend the ideas in Newton’s third law to propulsion. Because in effect, hydrokinetics theorizes that water particles are propelled toward the tooth with enough force to exert ablation. For a rocket to be propelled into the sky, it has nothing to do with the impact of the exhaust against the atmosphere. That is a very common misconception. What propels a rocket, is the recoil force of the exhaust molecules (system #1) pushing against the rocket itself (system #2). A pair of forces, opposing each other, with system #1 overcoming system #2 and the rocket moving up through the atmosphere.

You always need two systems. Here is another maybe easier example.

If your car runs out of gas, and you get out of the car and behind the bumper and push, as long as your force overcomes the force of the car and the friction of the pavement and surrounding air, the car will move forward. However, if it is raining outside, and you say “Hey , I do not want to get wet”, and push the car with the same force on the dashboard in the front seat (as you previously did out of the car and on the bumper), the car will not move at all.

Why?

Because you and the car (with you still in the front seat) are now the same system. For Newton’s third law to apply, there must be two separate systems (ie. You pushing behind the bumper or the exhaust molecules pushing against the rocket).

With the hydrokinetic theory as presented (in my understanding) we are only dealing with one system. There is nothing to push against. The theory as presented, has erbium incident energy vaporizing part of a water molecule and propelling the rest of the water molecule towards the tooth, with enough direct vector momentum to cause ablation of enamel. My main problem with this is Newton’s third law. Where is the equal and opposite force, to such an extent, to cause up to 16,000+ psi of pressure on the remaining water “particles” to propel them forward. To me it is all the same system, (one original water droplet) just like sitting in the front seat of your car, trying to move the car by pushing on the dashboard. This is my problem with it from Newton’s perspective.

2) Einstein’s Relativity

The second postulate of special relativity states that the speed of light in free space has the same measured value for all observers, regardless of the motion of the source or the motion of the observer: that is, the speed of light is a constant at 300,000 kilometers/sec.

If incident erbium energy (infrared light) strikes a water droplet in front of the beam, and the reaction (vaporization, hydokinetics, whatever) begins; long before even 1% of the reaction causing the hydrokinetics takes place, the rest of the erbium photons that did not interact with the water must have already hit the tooth and begun the thermal-mechanical ablative reaction that we all know. To state any different logic than this (because remember light travels at 300,000 kilometers/sec) is to say that the hydrokinetics is faster than the speed of light. Einstein says that is impossible. This is my problem with it from Einstein’s perspective.

Eric Bornstein DMD