Vita Easyshade Intraoral Dental Spectrophotometer

My dog's teeth are lighter than mine.

 

...And I have hard scientific evidence of that rather humbling fact.  The latest new dental technology that we've adopted is an electronic tooth shade taking device from Vita.  It is able to read the color of teeth- meaning their hue, chroma, and value, which I'll explain in a minute- with accuracy and precision.  Accuracy in this context means that the shade reading represents reality quite well.  Precision means that if we take multiple readings of the same tooth they will come out the same or very close to it- there's not a lot of variation with technique.

After many years of having no options other than some very unscientific, even irrational, shade guides in dentistry, Vident came up with the Vita 3D-Master shade guide:   

http://vident.com/products/shade-management/vita-3d-master-shade-guide/

 http://vident.com/files/2009/09/3d-master-brochure_linearguide.pdf

Any artist will find the brochure fascinating, as it deals with color science in unique ways. 

From the Vita brochure:

"All of the colors that can be perceived by the naked eye are contained in the color sphere pictured below.  The vertical axis is a measure of VALUE, or the amount of black or white.  The horizontal axis is a measure of CHROMA, or the intensity of the color, and the axis that swivels around the sphere is the HUE, or the color itself.  VITA studied many thousands of patients around the world and found that the range of natural tooth shades are contained in a banana-shaped area of the color sphere - teeth are white in value, with a slight reddish-orange hue and of moderate chroma."  Here is the diagram:

 

And here are the bananas- the location of standardized tooth shade tabs within the banana-shaped 3D space in the color sphere where human teeth can reasonably be expected to reside:

An older brand of dental shade guide:

 

The Vita 3D Master dental shade guide:
 

Now I may get accused here of nerding out, but this is so cool.  Note how in the older shade guide the tooth color tabs are randomly spaced out- one does not relate to another in any predictable way.  Also there are two tooth tabs that are outside of the banana!  (Taken out of context, that is an utterly fascinating sentence.)  It can be expected, based on Vident's extensive research, that no natural human teeth on the planet will match those two shades.  And we dentists spent all those years considering them...

In the Vita 3D Master shade guide, the teeth are arranged in a much more logical- and ultimately useful- fashion.  From Vident's brochure:

"The scientifically-developed VITA 3D-Master shade guide offers consistent, even distribution of shades within the tooth color area, providing consistent coverage of the range of natural tooth color as well as making the determination of intermediate shades much easier."

The actual device looks like this:

 

We still face challenges, however, in making dental restorations look just like their neighboring teeth, even when we have such a sophisticated tool for matching tooth shades.  The ambient room light is important- we have special flourescent bulbs in our office that are close to the spectrum of natural light; we also have windows that open to a northwestern exposure and provide gentle daylight when it's, well, daylight.  We also have to rest our eyes and then concentrate with no distractions when taking a shade for a restoration.  Additional clarity can be provided by staring at something blue for a minute before evaluating shades.  This is because teeth have a good deal of red and yellow hues in them; blue, being on the opposite side of the color wheel, counteracts this to an extent.  The color receptors in our eyes (the "cones") react to the blue wavelengths of light and are mostly at rest in regards to the red-yellow wavelengths; when we re-direct our gaze towards our patient's teeth we can better evaluate the hue because the cones are rested and ready to go.

Still, what if there was a way to measure a tooth's color objectively, without subjective (read- user error) factors getting in the way of success?  Well, now there is.  This compact and intuitive little beastie is the Vita Easyshade device:

 

We calibrate the device against a target disc of known shade, then aim it at our patient's tooth and obtain our readings.  We can take one general reading or three- one for each third of the tooth going from the gumline to the edge.  The enamel of teeth has varying thickness over the internal dentin, so multiple values can be important.

Another factor that enters into our ability to match shades of teeth and restorations is the age and wear of the hand-held analog shade guides themselves.  They do experience color shift with time- so an old one is not as accurate as a new one.  When we first got our unit I evaluated our two Vita 3D Master guides by checking the Easyshade values against the physical shade tab labels.  One of our guides is newer and it matched the electronic readings exactly.  The other is older and, alas, its colors have changed so much that I must consider it inaccurate.

When I registered my own tooth shades (it varies from tooth to tooth a little) I found that I was pretty much a 2R1.5:

 

The first number refers to the value, or lightness level (from 1 to 5).  The letter refers to the hue; in my case I'm a little more reddish than average.  The second number refers to the chroma, or color saturation (from 1 to 3).   Since lower numbers are lighter and less saturated, my teeth are a bit lighter than average.  We did whiten them a few years ago using our excellent in-office whitening procedure.  Yet it is time to lighten again a little (conveniently, in my Invisalign trays while I'm still moving teeth around!), since coffee, tea and many of the other things that we eat and drink have caused my pearly whites to become more like pearly beiges.  My terrier Nicky, who does not drink coffee (that I know of), has canine canines that are shade 0M1, which is so high wattage that he could be a weather person.

You see, of all Americans, the group that tends to have the lightest teeth is the entertainment industry.  And of the entire entertainment industry, I've casually noticed that weather people tend to have the very whitest teeth.  When I say white, I mean Hammerhill-Paper-Laserjet-paper-white.  It's silly to go that far and I don't agree with it personally, but as the bar keeps getting raised higher, the aspiring TV personalities' teeth keep getting whiter.

 

Comments

[Charley Burright]

A gadget that determines the color values of teeth? Does this mean the dentist will know how much whitening needs to be done for your teeth? If this would be the gauge then it could definitely help those patients, who need a little bit o' teeth whitening, in such a way that, the method to be used is going to be optimal.

[ahmed sleem]

i need that device for a dental research

[A_M_Alhandoodi]

It's a very good device