A brief guide to creating a gumshield (Rugby / MMA / etc) with non-toxic Instamorph. The resulting gumshield can be refined to be a tight 'snap' fit or a little l more loose.

The Instamorph gumshield is a stronger, more rigid gum shield than most commercially available "heat-and-bite" gumshields that I have seen and tried. This may be more beneficial for saving teeth in an impact with more focus (elbow?), But, but as any shock to the lower jaw will be more readily transferred to the 'brainy bit' of the head, this might make you more likely to get knocked out. but that is just me speculating. Id rather be knocked out and keep my teeth thanks!

DISCLAIMER: I am no gumsheild expert

STEP 1 (finally) Melt instamorph that is roughly 1 and a half times the size of your thumb (if the gumsheild is for you that is). I make an assumption that in general thumb size is proportional to jaw size ;-)

OK, the blob on the spoon in the photo is good for two or three shields!

Step 1: Shape It, Bite It.

Work the 'n' shape melted Instamorph into your cakehole.
gently hold and align it in all round your bite.
try to ensure it goes back to the molars on both sides
ensure the instamorph is still hot enough and gently bite down (transparent, no milky colour).
work the outside of the shield into a smooth surface, covering all the teeth - a little gum is fine too.
Work the inside of the shield into the teeth with your tongue.
Dont push so hard it gets too thin.
Once the shield has started to solidify, gently wiggle teeth and remove the shield.

Step 2: Remove It, Cool It

Once the shield has cooled to room temp, IT WILL HAVE SHRUNK SLIGHTLY. I haven't seen any temp-expansion figures for instamorph but the shrink can be significant enough to make it a small effort to click into place and much more of an effort to get out again! There was a comedy moment when I discovered this..... It is hard to laugh with carefully moulded lump of hard plastic holding your jaw closed.

Anyway...

Step 3: Refine the Fit.

If you wish, you can partially re-melt the surface of the shield in order to loosen the fit. I managed to loosen the bottom teeth fit more whilst keeping the top teeth fit fairly snug, so the shield doesn't fall out easily when you need to open your mouth catch your breath (which is quite often in contact sports!) , and this makes it easier to remove too.

I think this basic technique could be (and has been) used for creating mouth-held accessibility devices.