Novocaine is nothing if not an object lesson for men on keeping it in their pants. Frank Sangster, DDS (Steve Martin: Bowfinger), seemingly has it all: successful dental practice, the love of a beautiful woman — his hygienist, Jean (Laura Dern: Jurassic Park III). But a late-night appointment with a gal with Trouble written all over her (Helena Bonham Carter: Planet of the Apes, in skanky Fight Club mode) leads to a tryst in the chair, which leads to an investigation by the Drug Enforcement Administration, which leads to the wrath of Jean, which leads to things so much worse than you’d want to imagine. As a black comedy/crime thriller, this all-over-the-place flick is neither funny enough nor suspenseful enough to maintain much interest, and the coolly sophisticated Martin just comes across as too savvy a guy to have let himself get into this mess. Still, there’s one good thing about it: The power of association will make you hear Martin singing Little Shop of Horrors‘ “Dentist!” in your head for a week.