Materials that youíll need
Dental Casting Trays
Base Former Mold
Tooth Shade Acrylic powder
Gum shade Acrylic powder
Clear Acrylic powder
Acrylic Monomer liquid
Clear coat spray
Find a set of dental casting trays that fit inside your subjectís mouth. There should be plenty of room around their teeth when they are placed in their mouth. There needs to be room for the alginate after all. I find that medium sized dental casting trays will fit into most adultsí mouths. However, you should have various sizes available just in case you have to cast a very small or very large personís teeth.
You can buy very inexpensive disposable trays from one of the various make-up suppliers listed in the book or from a local dental supply store (maybe your dentist will just give you a set, ask). You can also buy stainless steel ones. I personally see no reason to buy the stainless steel ones; they are expensive and the plastic ones are just as washable and reusable as the steel ones.
The subjectís lips should be pulled over the casting trays; the tongue goes on top of the lower tray.
Dental alginate is especially formulated for casting teeth. What this essentially means is that it has a minty flavor and sets very quickly. I have used regular Prosthetic grade alginate for casting teeth and gotten excellent results. However, 5 minutes is an extremely long time to have a casting tray and alginate in your mouth and regular alginate tastes terrible, spend the money to buy the dental alginate.
Youíll want to put on glove before you put your hands near anyoneís mouth.Fill the casting tray with alginate. Spread it around to be sure that you havenít trapped any air bubbles at the bottom. Have the subject open their mouth wide and place the tray in their mouth. Have them bite down on the tray so that the alginate surrounds their teeth. If their teeth hit the bottom of the tray, have them open their mouth slightly. If you the subjectís teeth are resting on the bottom of the tray the tips of their teeth will be cut off of the finished cast. Their teeth need to be surrounded by alginate. Make sure that the subjectís lips are outside of and wrapped around the tray.
The subject should lean forward as you cast their teeth. When they bite down on the tray, the extra alginate in the tray will be squished out. If they are leaning forward it will go out their mouth, otherwise it might go down their throat and chock them.
Once the alginate has set the subject can start to remove the tray by pushing at the tray with their tongue. Grab the handle of the tray and help them. The alginate will have a strong suction against their teeth and gums; youíll have to break this suction to remove the tray.
Wash any remaining saliva, and in some cases blood, from the cast. Blood in the cast is from people with sensitive gums and gingivitis, you didnít do anything wrong, but your subject might want to see a dentist.
If you intend to cast the lower teeth or put off filling the cast for any reason you should soak it in water so that it wonít dry out.
Casting the lower teeth is almost identical to cast the top teeth. The only real difference is that you need to mix the alginate a little thicker since the lower tray must be inserted upside down; you donít want the alginate dripping out. Also, the subjectís tongue goes on top of the lower casting tray.
FILLING THE CAST
Remove the tray from the water that you were soaking it in and dry it off. Use a q-tip to remove water that has settled inside of the tooth cavities. Mix up a small batch of Ultra-cal 30 and carefully apply a thin layer in the tooth cast. It is very to trap air in the many nooks and crannies of the tooth cast. Continue fill the cast until the tooth and gum areas of the cast are filled
As the Ultra-cal set it will thicken up allowing you to build the material up a little. Latter will be adding a base to the tooth cast so that it will be easier to handle. To do that we will simply be inserting the cast into some wet plaster, for this reason we want to make the bottom of the cast choppy and uneven. Weíre purposely making undercuts so that the wet alginate will be able to grab onto the cast.
When the Ultra-cal has set remove the tray and pull the alginate off. It should come off fairly easily, if not, tear it off.
The next step is to insert the tooth cast into itís base. However, as Iíve said before, the already set plaster (the tooth cast) will suck the water out of the wet plaster making it weak and powdery. To prevent this you should soak the tooth cast in water for about a Ĺ hour.
They make rubber base form molds that give your tooth cast a nice professional look. They are used so that a tooth cast can be installed onto a jaw reticulator. This allows you to see how the teeth on the top and bottom jaw line up. I donít usually use these; I just eyeball to see if the jaws line up. You can buy one if you want, but they really are not necessary. I usually cut a plastic cup from McDonaldís or elsewhere and use the bottom a base former. This works just fine.
After your cast has soaked long enough, take it from the water and dry it off. Mix a thick mixture of Ultra-cal 30 and fill the bottom 1" of the cup. Gently tap this on the counter top to release trapped air bubbles. Place the cast, tooth side up on top of the ultra-cal. If the cast sinks in the plaster remove it and allow the plaster to thicken up for a little while.
When the tooth cast is in place I use a small brush to blend the wet plaster up onto the tooth cast and smooth the whole thing out. Then I allow it all to set.
Flex the bottom of the plastic cup and the plaster tooth cast will pop right out. Fix any imperfections with a chisel, knife, sandpaper, Dremel tool or whatever else it takes.
What kind of special effects artist would you be if you werenít able to make fangs for your vampire or rotted teeth for your hobo. Like I said earlier, the more you change one part of the person the more youíll need to change the rest. As a make-up effects artist you should do anything that you need to do in order to bring your character to life, this includes changing the inside of the subjectís mouth as well.
As I always do, Iíll start by telling you a little bit about the materials that you will be using. The dentures themselves will be made using a two-part acrylic. One part is a powder that comes in various colors and the other is the liquid that activates the plastic. The powder is called Monomer and the liquid is called polymer. The powder comes in many different tooth shaded colors, several pink gum colors and clear. The liquid works the same no mater what color that you use. When you mix the monomer and the polymer they make a gel that hardens into a tough plastic in about ten minutes.
The clear is used to extend the other colors. What that means is that you can mix a little bit of clear into the pink and you getÖmore pink. That is a very handy piece of information that I stumbled on, you can mix monomer at a ratio of up to 40% clear to 60% color before there is a detrimental color difference (then again, try it out you may think of a creative use for the new color).
You can also mix the colors together to make new colors. I usually buy a large bottle of very dark and very light tooth shade acrylic; I can mix any shade in between myself.
Dental acrylic is a hazardous material! Always wear rubber gloves and work in a well-ventilated area!
The method that I use to make teeth involves making (or buying) acrylic teeth, attaching the teeth to the tooth cast and adding gum material to hold the teeth in place.
Weíll start my making the teeth. Place an eyedropper full of polymer into a glazed ceramic or metal dish. You cannot use plastic, as the polymer will melt it. Sprinkle monomer from an eyedropper over the liquid. Stir wit a toothpick and add more powder until you have a thick paste. Scoop up the paste in your gloved fingers and begin rolling it into the desired shape. The acrylic paste may be a little sticky at first, but it will dry and become less sticky in a short time. Because of the way the material sets you wonít be able to form a perfect tooth like this, but you can get close. Just form the acrylic into the basic shape of a tooth. Youíll need to make this rough shape a little bit larger than you intend to make the finished tooth; youíll be grinding away at the tooth to get the final shape and youíll need the extra material so that you end up with a tooth that is too small.
Use a Dremel tool, files, and an ex-acto knife to shape the final tooth. If you run into any trouble while carving your tooth, just look in the mirror or find a dentistry book from the library to use as a reference.
Once you have the tooth in the shape that you want it you can sand it smooth it out using a nail file or fine grade sand paper.
The next step is to arrange the teeth on the tooth cast the way that you want to appear in the finished dentures. First of all Coat the tooth cast with Vaseline, this coating of Vaseline will help the acrylic teeth from sticking to the plaster. Next decide how you want the teeth to be arranged on the cast. Use a small ball of clay or wax to hold them in place. Attach them from behind so that you are free to "drop" the acrylic powder and liquid onto the front part of the tooth cast.
Set the cast onto the lower tooth cast and see how the two jaws will line up. If you can clearly see that the dentures will interfere with the subjectís real teeth or the lower set of dentures then they will likely cause the wearer discomfort or impede their speech.
Now itís time to add the gums. Drop a small amount of acrylic liquid onto the tooth cast where you plan to have the gums. Next sprinkle a little bit of powder on top of this. The powder will soak up the liquid. You can continue to add the pink gum powder in this manner until you have built up enough gums. Use a metal sculpting tool to shape the pink acrylic as you add it; in this way you can arch the gum over the teeth or sculpt any detail that you see fit. Of course the liquid and powder will also stick to the teeth as this process progresses, youíll have to be careful not to allow any gum acrylic to get on top of the teeth. You may add a small amount of Vaseline onto the parts of the teeth that you want to show. That way you can always scrape off any acrylic that builds up on the teeth where you donít want it.
When you have the front of the gums built up, remove the clay or wax from the back of the teeth. You can now begin to build the back of the teeth in the same way that you built up the front. You donít need too much acrylic on the back of the teeth to hold them in place, just a little to overlap and clip onto the teeth. In fact, the less acrylic in the back of the teeth the less speech is impeded.
Once the acrylic is set (this happens fairly quickly) you can pry the dentures from the cast. Use a Dremel tool to trim them up and remove any rough spot. Have the subject try them on. If they report any spots that rub then trim the done some more until they are comfortable to wear.
Once they are trimmed to your satisfaction it is time to paint them. There is a product called Minute-Stain that is especially made for painting acrylic dentures. However, it is very expensive. In fact, I have never even tried it. I use plain old acrylic paint. At a craft store they usually sell a wide variety of inexpensive acrylic paint in little bottles, this stuff is pretty good for the purpose. Pick out a few pink shades to decorate the gums a few browns, a few yellow and any other colors that you think are appropriate. For the dentures that I use as an example in the pictures I used clear acrylic for the gums and just painted them pink. A little bit of red around the teeth adds a gingivitis look to the dentures.
For the teeth I just added some browns and yellows around the gums. Actually I more stained the teeth then painted them. I applied the paint in the area that I wanted it then I used a damp Q-tip to wipe off the extra, leaving behind a film of paint.
Always look for reference material. Look up dentistry on the Internet or in the library, youíll be able to find a lot of photos to use as inspiration.
When the teeth are done being painted, spray a few coats of ClearCoat to give them a shiny, wet look.
Store the teeth on the tooth cast.
Because the dentures are made on a tooth cast of the subjectís teeth, you will not need any denture cream or anything to hold them in. They will stay in just fine all by themselves.