Signs that your dentist is a sadist: The patient chair has restraining straps. There is blood splatter all over the ceiling. When you scream, he laughs. The windows are blacked out. Instead of taking X-rays, he takes core samples. The hygienist wears skintight leather and carries a whip. The room is soundproofed. The dentist's drill is a Black & Decker model. You have to sign a form in advance promising not to press charges.