The title of The Secret Lives of Dentists suggests a quirky, lighthearted comedy, but Alan Rudolph’s study of a troubled marriage includes as much anguish as sardonic wit. Campbell Scott, who co-produced this adaptation of Jane Smiley’s novella The Age of Grief, stars as David Hurst, a suburban dentist who shares his practice with his dentist spouse, Dana (Hope Davis). The Hursts ostensibly enjoy a solid union, but when David unexpectedly appears backstage at an opera production in which Dana is performing, he catches her in a seemingly adulterous embrace with another member of the company. His heartache is exacerbated when trumpet-playing Slater (Denis Leary), a raunchy, outspoken new patient, publicly complains about the quality of the dental work he’s received. Afraid to confront Dana, David begins to fantasize encounters in which Slater upbraids and taunts him: “Kill her; I would.” David’s mute suffering intensifies as, on top of everything else, he and his family members succumb one by one to a disabling flu. Sporting a Kevin Kline mustache, Scott is subtly convincing as a man immobilized by the prospect of losing the life that he has painstaking constructed. Davis’ Dana, meanwhile, is intriguingly enigmatic, distant and moodily unfulfilled by her relationship with a man whose self-control prevents him from tapping into her repressed romanticism, and Leary is suitably oily as David’s swinger alter ego. But the cast cannot overcome Craig Lucas’ screenplay, which sets its characters and conflicts in motion and then quickly runs out of steam. Although initially amusing, Slater’s macho manifestations grow so tiresome that one begins to regret the conceit. The family’s illness, which consumes the final third of the movie with torrents of actual and metaphorical purgation, similarly palls. In the past, Rudolph has met much more imaginative challenges: a blues-tinged feminist-revenge melodrama in Remember My Name, a noirish urban fairy tale in Trouble in Mind, a deliciously erotic roundelay in Choose Me—all from original scripts the filmmaker wrote himself. By the time Dentists reaches its telegraphed resolution, you’ll wish that Rudolph had kept to himself this time around, too. —Joel E. Siegel