Ilesanmi, 19, has impressed since returning from a loan spell with Histon, featuring in the Daggers' last five games.
Gwillim, 27, has played just three times since joining Dagenham from Histon in the summer.
His only start came in a Johnstone's Paint Trophy clash with Charlton in August and he has since made just two appearances, both as a substitute.
He arrived from the Stutes in June after playing over 100 games in three years at Bridge Road.
Wimbledon boss Terry Brown has been on the look out for a left-back since Chris Bush's work experience stay at Kingsmeadow was ended by parent club Brentford.
Ilesanmi played 16 times during his two-month loan stint with Histon.
Stutes boss David Livermore was keen to keep hold of the former Ashford Town man but Dagenham decided to retain the player.
Source: BBC Sport
Source: BBC Sport