‘That’s My Boy’

To say Adam Sandler’s new movie isn’t as bad as his last is like saying your typical dental filling isn’t as bad as a root canal. Neither will kill you, and with today’s anesthesia, they may not hurt that much. But there’s no way you want to be in that reclining chair, with sharp metal objects shoved in your mouth.

So why do we keep renting those comfy, stadium-seating cinema chairs and letting Sandler shovel something else down our throats?

“That’s My Boy” is hardly Sandler’s worst, and next to last year’s abysmal “Jack and Jill,” his latest one looks almost inspired. Yet this father-son story is just more of the same gross, lazy comedy that Sandler’s been doing for years, the repetitiveness evident in his generally declining box-office receipts.

Sandler’s audience is outgrowing his movies, even if he isn’t.

The idea behind the movie isn’t half bad and provides some parallels to Sandler, a guy who’s made a career out of stunted adolescence. In this one, he plays a middle-aged loser who was in his early teens when he knocked up his seventh-grade teacher and has been the world’s most infantile dad to his boy ever since.

You know the formula: Sandler’s Donny Berger has to grow up in some fashion by the end of “That’s My Boy,” while his estranged son, Todd (Andy Samberg), must come to appreciate the unique upbringing received at the hands of his dad, even if Donny didn’t so much rear him as rear-end him.

Now a neurotic but somehow successful Wall Streeter, Todd is preparing to marry his dream girl (Leighton Meester) when Donny barges back into his life, scheming to fix his own financial problems and reconnect with the son he hasn’t seen in more than a decade.

From this premise, we get vomit jokes, strip-club routines, fecal humor and gags about masturbation, including with pictures of old women. In short, we get Sandler, doing what he always does, with whatever edge he once had continuing to erode as he ages and looks sillier at what he’s doing.

With some thought and effort, “That’s My Boy” could be fresher, smarter and much, much funnier, while still retaining all the gross-out gags and idiocy that Sandler loves.

The 45-year-old Sandler could have grown up a bit along with Donny, a good career direction if he hopes to keep this crap up as he nears AARP eligibility age.

Sandler, also a producer on the movie, as well as director Sean Anders and screenwriter David Caspe stay on the really stupid end of stupid, though.

As Donny, Sandler clunks people on the head with booze bottles, flaunts his outrageous erections in people’s faces and shouts “Wazzup?” far too many times.

Bearing some physical resemblance to Sandler, Samberg is well cast as Donny’s son, and he plays the straight man well enough for his “Saturday Night Live” predecessor.

Other casting choices range from clever to weird. Susan Sarandon and real-life daughter Eva Amurri Martino make a spitting-image duo as the older and younger versions of Donny’s seductress teacher. Genially playing a variation of himself, Vanilla Ice is kind of funny as an old pal of Donny. James Caan must have too much time on his hands, though, popping up for some strained scenes as a boxer-turned priest. And if you bother to cast Tony Orlando in something more than a bit part, why not go the extra mile and work in the singer’s old backup group, Dawn?

Sandler could have found a way to weave them into Donny’s fan club. Almost everyone he encounters loves Donny, but those are actors getting paid for it. The audience of “That’s My Boy” is paying them – and paying Sandler his millions – money better spent on whatever dental work you’ve been putting off.