There can be quite a wide variation in the color of the natural teeth present in any single mouth, as well as a wide variation in the color of different parts of the same tooth. It is not unusual at all to place a lighter color on the "biting surface" of a tooth and a more intense color closer to the gumline of the same tooth. That is how nature does it and we Dentists often try to do the same.

I think it is a very good thing to blend the colors of crowns. The colors on the biting surface depends on the tooth itself. A-1 and A-2 are on the lighter end of the shade guide. If your displeased, just talk to your dentist and see if there is anything they can do.

Teeth as a whole have many shades present and are usually darker and more opaque at the gum line. If your dentist placed composite in the biting surface of upper teeth, it would be very difficult for someone at a normal distance to detect the difference. You should discuss this with your dentist if you have a preference for shades as there are many to choose from.

The shade of your upper teeth compared to your lower teeth may not necessarily be the same. I'm sure your dentist picked the shades that best matched your teeth.

Your dentist chose to blend two shades within the same family of colors (A1, A2, A3, A3.5 and A4) to create a more lifelike and realistic looking crown for tooth #19. Oftentimes, we will also blend composite shades as well when doing a tooth-colored filling. My guess is that your dentist felt the single shade of composite for your fillings was a satisfactory choice.

Without seeing photos of your teeth, i can't tell you why those shades were selected. Typically, the biting or chewing surfaces tend to be lighter than the gumline. This is due to thicker dentin/thinner enamel at the gumline and since the shade of the tooth is mostly derived from dentin (which tends to be darker than enamel) the gingival 1/3 of the tooth can be a shade or 2 darker than the incisal/occlusal surfaces. The incisal/occlusal surafaces are mostly enamel and tend to be lighter than the gingival 1/3 of the tooth. Hope this helps!

Maybe your dentist felt that A1 on #19 was the best color match since it still is in a visible position in your mouth. however, you usually won't ever see the biting surface of #2,3 so your dentist probably picked a shade that would work well in your mouth. But for the best answer, you should ask your dentist.

Generally crowns and natural teeth with composite fillings are hard to match to each other and in this case where these teeth are on opposite sides of the mouth, the main issue should be , Does the crown match the teeth on either side of it? Matching natural teeth with filling materials is one of the most difficult things a dentist has to deal with!

The color of any natural tooth is polychromatic, meaning there is variation of colors through out the tooth due to thickness of dentin and enamel. Your teeth naturally have darker color at the neck of the tooth toward the gum line, and a brighter color toward the edge of teeth or chewing surface, If your dentist placed A2 neck and A1 for the rest of the tooth, he was trying to make your dental crown more natural looking, however it does need to be matched with the adjacent teeth, not brighter or darker. If that is the case, and your crown matches the adjacent teeth, your DDS did a great job !

Now for dental white fillings such as composite fillings, an A2 color usually blends well with the tooth, since it is natural color and it is the most common natural color in dentistry. Again the most important factor is if white composite filling matched the tooth , and the surrounding adjacent teeth, so it does not stick out !

One more thing, be aware that dental fillings, and your crowns do not whiten or bleach, if you were considering to whiten and bleach your teeth later on, and that is one factor that the cosmetic dentists consider when they are selecting a color.Sometimes the cosmetic dentist selects slightly whiter color compared to adjacent teeth, when both you and your dentist have agreed to have teeth whitening or bleaching treatment done.

Hope this helped you.