In JM Barrie’s Peter Pan, the good fairy Tinkerbell drinks poisoned medicine and prepares to die.

The only way to save the sprite from her grim fate is for the audience to prove they believe in fairies.

‘If you believe, clap your hands.

Don’t let Tink die!’ shouts Peter and sure enough, children and a fair few adults launch into deafening applause to rouse Tinkerbell from her deathly slumber.

More than 100 years after Pan first took flight, children are asked to believe in fairies again in Michael Lembeck’s saccharine fish-out-of-water comedy, which hammers home the idea that children should be allowed to wallow in fantasy.

Derek Thompson (Dwayne Johnson) is a veteran ice hockey player who has acquired the nickname of Tooth Fairy because his aggressive play frequently relieves opposition players of their bicuspids.

‘You cannot handle the tooth,’ Derek screams to his adoring fans.

While he excels on the ice, Derek struggles to connect with 14-year-old Randy (Chase Ellison) and five-year-old Tess (Destiny Whitlock), the children of his girlfriend Carly (Ashley Judd).

It doesn’t help that Derek insists on trying to dissuade the youngsters from believing in the real Tooth Fairy, Santa Claus or the Easter Bunny.

As punishment, Derek is sentenced to serve one week as a tooth fairy, sprouting wings whenever he must recover a tooth from beneath a child’s pillow and leave a dollar bill in its place.

Chief Tooth Fairy, Lily (Julie Andrews), assigns administrative fairy Tracy (Stephen Merchant) to look after Derek and ensure he completes the seven days.

Wise old coot Jerry (Billy Crystal) then arms Derek with the essential tools of the fairy trade: a wand, dog bark mints, shrinking paste, invisibility spray, a klaxon that scares away cats and amnesia dust.

Through this unusual community service, Derek gains a healthier outlook on life and finds a way to win the trust and affections of Randy and Tess.

Tooth Fairy is smothered in enough emotional syrup to rot the pearly whites that Derek is asked to harvest, but Merchant’s acidic asides help to cut through some of the mawkishness.

His unlikely double-act with Johnson, who is great at physical comedy but struggles with anything approaching emotion, produces a gurgling of laughs.

Andrews merrily recycles her performance from The Princess Diaries, while the younger performers look adorable as the plot shamelessly steals from Love Actually to provide Randy’s storyline with its crescendo.

Young audiences will giggle at the pratfalls and parents can rest their tired eyes every time Merchant is off screen.

To borrow one of Derek’s groansome catchphrases: ‘That’s the tooth, the whole tooth and nothing but the tooth.’

• Release Date: Friday 28 May 2010
• Certificate: PG
• Runtime: 101mins