Scroll down and click on the 2nd box (says Free Sample on it). They will have you register and then you can fill out for a sample.
NOTE: After you make your account it will take you to a page saying Update Your Account Information. Just click on the Dentek logo in the upper left corner to go back to the main page and click the free sample box again. This time your info will be entered in the boxes. Make sure everything is correct and filled out and then submit and you are done!