Frank Sangster may be the perfect dentist. He’s charming, friendly and is more than a little liberal with the nitrous oxide. With his firmly established practice and oncoming wedding, it seems that everything in his life is perfect, and yet somehow his life’s gleaming exterior conceals a dark, rotten core.

With a predictable plot and severe narrative overstatement, Novocaine (Artisan Entertainment) drills the metaphor of the rotten tooth so deep it hits bone. As Sangster, Steve Martin’s cheery appearance should be counterbalanced by his voiceover, but lines like “I’ve always said that the worst thing that could happen to a man is to lose his teeth.and I should know,” sound more like they come from a talking toothbrush in a health class filmstrip than from a secretly sinister dentist.

The trouble starts the moment Sangster walks into his office and finds a tiny, black-clad nymphet seated in the dentist’s chair. She complains of a toothache, but he soon realizes she wants only a prescription. Instead of kicking her out, the good doctor is too taken by Susan (Helena Bonham Carter) to refuse, and gives her a script for just five pills. This minor infraction sets off an unsurprising downward spiral, as Susan takes him to bed – or technically, the dentist chair – and then takes him for all he’s worth. Soon enough, Sangster is discovering bloody bodies covered with his own bite marks in his home, and yet every plot twist comes too late to shock an overprepared audience.

Martin cannot shake the nice-guy voice and demeanor. So while the devilish Carter (Fight Club) darkens the edges, Martin’s oppressively sunny disposition washes out every shadow and nuance.

By the time we reach Novocaine’s obvious conclusion, director David Atkins has overextended the tooth metaphor further than seemed possible. Most relieving is the knowledge that Martin’s unbearable narration is over. One more shot of the dentist’s interminable smirk and someone would have to knock that perfect set of teeth right out.
Novocaine is in theaters Friday.