Instruct: Classify a review into positive or negative sentiment.
Query: DENTAL HYGIENE MOUTH GUARD ABSOLUTELY TERRIBLE

THE DENTAL HYGIENE PREFERRED MOUTH GUARD IS ABSOLUTELY TERRIBLE. NEITHER THE TOP OR BOTTOM GUARD WOULD FIT MY TEETH EVEN AFTER TRYING 3 TIMES OF SOAKING THEM IN 60 SECOND COOLE DOWN BOILING WATER. ALSO, EVERY SINGLE MORNING (AFTER INSERTING EITHER MOUTH GUARD IN MY MOUTH BEFORE GOING TO BED) I WOULD WAKE UP AND THE MOUTH GUARD WOULD EITHER BE UNDER MY PILLOW OR ON THE FLOOR -- NOT IN MY MOUTH WHERE IT SHOULD HAVE BEEN. I WOULD NEVER EVER AGAIN BY THIS PRODUCT. IT IS A JOKE. IT IS A FRAUD. I FEEL AMAZON.COM SHOULD REFUND ME MY MONEY BACK. SINCERELY, BOOTS