My favorite filling material is a mixture of cyanoacrylate cement and dental acrylic powder. I’ve tried a number of other materials, microballons, baking soda, different cyanoacrylates, etc., they either don’t work at all or aren’t even close to this material. There are no solvents, so the plastic is not softened and can be sanded as soon as it is hard, which is usually within 5 to 10 minutes, depending on how thick you make it. It is also great for reinforcing joints.
Dental acrylic is the material used in the fabrication of dentures. There are several different forms of the powder. All of them will work with this method, but the Dentsply Free Flow that I use works the best. In dentistry, the powder is mixed with a monomer to form a resin. Some forms of dental acrylic resin will cure within a few minutes under warm water, while others require much more heat for a number of hours. The Free Flow powder that I use is meant to add to an auto curing resin to make it flow better and will not cure on its own like a typical dental resin.
The cyanoacrylate that you need is Zap-A-Gap, Fig. 1. I like to mix the cyanoacrylate and powder together on a thick, slick piece of paper. I usually cut up a thick magazine cover or old calendar. Don’t use porous paper because the cyanoacrylate will just go right through. Squeeze out an amount of cyanoacrylate on the paper first, Fig. 2. You then add the acrylic powder, Fig. 3. It works best if you add a little and stir the mixture quickly to incorporate the powder into the cement, Fig. 4. You can then add more powder to make it as thick as you want. The thicker you make it the faster it sets. Make up a few tests and see how it mixes and handles. I’d be willing to bet that once you get the hang of this, you will find a number of uses for it.
