This is a complete solution to the island, including spoilers. If you wish to play the game, hints are available at the Poptropica site.
(For the Shark Tooth Island guide on the Poptropica site, see the related link).
SOLUTION :
its OPEN
To get the ingredients on shark tooth island,you must open the door in the cave,get the 2 ingredients and go back to the native islander and give him the stuff
open
go on top of the temple and get the paper then go to the door and spell open with the symbols on the piece of paper then the door should open
open
open
open
It is OPEN which is the 3rd 4th 6th and 7th teeth counting from the left. Then you click the nose.
you put open 4 de answer
Spell the word "open" in ancient symbols using the translation page. (see related question)
In the underground ruins on shark tooth island, you need a code to open the stone door. It is the word "open" in the hieroglyphics from Hammerhead's journal. The journal page is on top of the ruins, and you can get it by climbing the vine to the first platform, then jumping left. The word "open" is spelled by pressing the 3rd, 4th, 6th, and 7th symbols from the left, and then pressing the nose.
Use the translation in the ruins to press the four teeth that spell "open", then press the nose to open the door. (see related question)