LED Curing Lights

I am in dental school right now and have been seeing ads for new LED curing lights for use with tooth-colored composite resins. The one I saw looked about the size of a sonicare toothbrush and was advertised as having a six minute runtime between charging. They were charging $600 for it.

The polymerization reaction in composite materials is initiated at a peak of 470 nm. The curing light I have now uses a projector type bulb that is filtered to provide the right wavelength, hence the blue light you see the dentist put in your mouth.

Have any of you seen these (LED type) or know enough about to describe their internals to me. I have to think that with the collective knowledge of this forum I could find out how to build my own killer curing light for <$600. But I may be completely wrong.

My main questions are what type of LED they use, how they would get the right wavelength, and what type of battery source do you think they use. My curing light is quite bright and I imagine the LED type should be similar. It is not so bright however to make me think that a six minute runtime is all one could get from a power source.

Any ideas would be appreciated. I don't know much more than the basics so any knowledge you have would be enlightening.

As far as I know, the toothbrush looking thing is made by 3M, and has 12 465nm LEDs in it in a clever configuration with a 3-level faceted reflector that makes it very thin like a pen, which is why it's thinner than it might appear if you were told there were 12 LEDs in it. It probably has a light pipe as the opening also.

We have a 465nm photo-polymerization flashlight, but is rather too big to fit in the mouth except for dental work on sharks and elephants, and possibly tigers, lions, and monkeys that can open their mouths really wide /ubbthreads/images/graemlins/smile.gif

The 465nm wavelength is also popular for exciting biofluorescense, especially in underwater organisms, which is why we also offer it in a TekTite diving light body.

So, to answer your question, yes, 465nm LEDs (usually speced 460-470nm, or possibly 465-470nm) can be used to trigger the resin polymerization reaction.

Hope that helps!
Piers

So does that mean I can cure teeth in the dental office with my $26 Royal Blue modded flashlight? /ubbthreads/images/graemlins/grin.gif

Cool pics! I am not sure if royal blue is the right wavelenght, but there is a "dental blue" Lux.

When I get white fillings at the dentist, he uses a pistol shaped light to cure them. After about 10 seconds or so, a fan turns on inside the unit, so there's some serious heat being generated. He wears special glasses also, so there may be a strong UV component of the light. I'd be careful, myself. YMMV.

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greenLED said:
Cool pics! I am not sure if royal blue is the right wavelenght, but there is a "dental blue" Lux.

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Come on it's a McGuyver thing. The royal blue is 460 nm hmmm...?

My dad has a curing light that has some sort of blue lux V driven by a lithium ion battery and some sort of driver, since it has programmed times and stuff. It looks like one of those sonicare toothbrushes. It doesn't get very hot, but then again, it only gets run for about 30 seconds at a time. It was $300.

According to the Lumileds site:
Blue: 470 nm
Royal Blue: 455 nm
Dental Blue: 460 nm

Does this small difference in wavelength influence curing time/ability? We should ask my brother, he's a dentist! Sadly, as much as I've tried he still thinks Maglites as top of the line flashlights. /ubbthreads/images/graemlins/jpshakehead.gif /ubbthreads/images/graemlins/grin.gif

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greenLED said:
Does this small difference in wavelength influence curing time/ability? We should ask my brother, he's a dentist! Sadly, as much as I've tried he still thinks Maglites as top of the line flashlights. /ubbthreads/images/graemlins/jpshakehead.gif /ubbthreads/images/graemlins/grin.gif

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If he has a Mag you should take it, mod it, and then give back and watch the amazement when he hits the switch. /ubbthreads/images/graemlins/smile.gif

The absorption curve of light that initiates the polymerization peaks at 470 nm but the curve is broad enough on the graphs that I have seen that 5 or even 10 nm off would still work, just not as well. But restoring people's teeth is not something that should be done halfway. 470 nm is the ideal. The standard curing lights I just read use a Quartz-Tungsten-Halogen bulb. This is what is in my curing light and it does create a lot of heat. All curing lights that I have seeen also have an attached filter or some other method of protecting the eyes. A curing light using LEDs would not have this same problem with proper heatsinking. Especially since they run for short periods of time as was mentioned. As an extension of my interest (obsession according to my wife) in flashlights I thought it would be very cool to have a homemade curing light. It would cause quite a stir at school especially among faculty who would probably not allow it. In thinking about it there are some issues that I would have to address since production lights go through testing etc. to quantify their effectiveness. Also there are features they have that I think would be hard to reproduce in a homemade light(without too much time or money) such as variable timers, bases, ability to clean/sterilize, and an overall professional appearance. I can just see the faces of people as I tell them I am going to put something in their mouth that looks like it used to be a m@g.

Well, it's probably not the best idea after all but I still think it would be great just to have one so I could say I built it myself. Does anyone know if fiber optics or "light tubes" are generally available for conducting light to the end of a light probe ~13mm in diameter?

FWIW, I looked up a bunch of LED lights from 3M, Whaledent, Dentsply, etc. and they range in price from $600 to $2000. Do you know who makes the $300 one?

Very interesting read.
So you are saying someone can geta few LED's of the right wavelength and build a light.
Then get some of the resin, if the sell it and work on your own teeth.
Do i have this right?

spidey

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spideyfan said:
Very interesting read.
... and work on your own teeth.
Do i have this right?

spidey

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Did you see the Mr. Bean where he worked on his own teeth, pulling one -- then discovered he had the xray back-to-front, and then pulled the next tooth, etc? He had knocked out the dentist somehow playing with the exam light i think.

You can't really work on your own teeth. You need some dentist etching acid stuff, water and air jets, and after using the resin stuff and the curing light, you have to use a drill to grind the filling into shape. But, you could if you are either really, really stupid, or really, really good with a dremel. /ubbthreads/images/graemlins/wink.gif

Well, without knowing a thing about what I was doing, I started useing some UV-curing adhesives a while back. They all seem to have different requirements... and I just happen to have some different UV LEDs to match! They will ALL cure the different adhesives - but some are much quicker to do the job than others. So basically, you simply need to match the LED frequency with the specific adhesive for quickest cure. I don't think there is just ONE perfect wavelenght for this stuff - but maybe they've standardized on something in the dental industry. That would make sense!

There are so many different resins out there that I wouldn't even take a guess but for the most part they use a couple of the same polymers in the continuous phase with camphorquinone as initiator. It is actually the camphorquinone that is excited by the light and begins the reaction with the polymers. The absorption spectrum I'm looking at right now shows that initiation of the camphorquinone can begin anywhere from ~430 to ~500 nm with the peak being 470 nm. Lights used in practice today (info from my textbook) peak at 430 or 470 nm for plasma arc, ~470 nm for halogen and ~500 nm for laser curing. So a 460 nm spec'd dental blue lux V from lumileds should work just fine if some of these others are outliers from the peak curve but are still used in practice.

So Darell you are correct that there is some standardization and also that there is not just one magic wavelength.

My light is a "gun" shape but relies on a separate box power source plugged into the wall. For making my own I was thinking of the toothbrush size but to make it easier I suppose I could get an old "gun" portion of my model and put a heatsink and led in it and use the stock optics to get the light where I need it. Instead of having a huge box and power cables I'd just have a charger that could plug into the side of my light when the batts got low. When in use it would only be the gun with no attached cords. That would be cool. More inconspicuous than a strictly homemade light. Fellow students and faculty would look on in wonder as I cured resin without any apparent power source!

Sorry.

Thank you for indulging my photon phantasy. (That would be a great screen name. Does someone have it already?)

Cypher Wrote
Does anyone know if fiber optics or "light tubes" are generally available for conducting light to the end of a light probe ~13mm in diameter?

Try a bore light for looking down the bore of guns.
http://www.sportsmansguide.com/cb/cb.asp?a=55627
The light pipe is usually bent at about a 45 to 90 degree angle and I bet it could be modified with a blue lux.

T3

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Darell said:
Well, without knowing a thing about what I was doing, I started useing some UV-curing adhesives a while back. ...

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Were you working on your own teeth? Heh, heh /ubbthreads/images/graemlins/smile.gif

I tried this today with a 3w and 5W Royal Blues

An odontologist came to my office just to test this /ubbthreads/images/graemlins/smile.gif

We tried with 3 compounds on actual teeths (not ours of course), all worked like a charm after 25seconds of exposure

He tried two filling compound and something like a primer used before applying the filling.


I may do a NEOCA Dental soon /ubbthreads/images/graemlins/smile.gif


Pablo

I use the blue-light-cured resins in fly tying. I have a couple of curing lights... one is a fairly fat, multi-LED model that takes three AAAs, I believe. But the other is a laser! It's nice and thin, but it almost works too well. If you have anything more than a thin film of the resin to cure, it cures it so fast it smokes!

Take it easy,
Bob