Two and a Half Men, The War Against Gingivitis

ASHTON KUTCHER joins the cast in the season premiere.

JUDY GREER is introduced as Bridget, Walden's ex-wife.

Alan prepares Walden for a date with Bridget.

On the rebound, Walden goes looking for Mrs Right.

Alan struggles with Lyndsey's risqué movie past.

Walden meets a girl who looks just like Bridget.

Jake's crush (MACEY CRUTHIRD) has a crush on Walden.

Walden's redecorating sends Alan over the edge.

Alan's sanity is tested upon release from the hospital.

Walden tentatively re-enters the dating world.

Bridget reappears in Walden's life... and so does Rose!

Walden's mom (MIMI ROGERS) reveals a secret about his past.

Walden enlists Alan as an ally in a boardroom battle.

Zoey pressures Walden to trim his hair and beard.

Walden tries to loosen up Zoey by sharing a couple of Berta's 'special' brownies. MATTHEW MARSDEN guest stars as Zoey's ex-husband, Nigel.

A storm traps Walden, Alan, Zoey and Lyndsey in the house.

Walden shares his feelings during a near-death experience.

PATTON OSWALT stars as Walden's ex-business partner.

Alan and Lyndsey introduce their mothers to one another.

Walden tells Zoey he's going into business with his ex-wife.

Zoey and Ava move in with Walden on a trial basis.

Charlie Harper returns from hell in the form of KATHY BATES.

On the 200th episode, Alan returns home from the hospital.

Jake decides his future in the ninth season finale.