Lindsay Lohan found a way to spend her day after being rejected from her community service this morning at the LA County Morgue ... at the dentist!

After her dad Michael Lohan blamed her yellow teeth on drug use during an interview on HLN's Issues with Jane Velez-Mitchell, Lilo paid a visit to her dentist in LA to get her chompers brightened.

Lindsay left the dentist's office covering up her mouth. Can't wait to see those pearly whites, Linds!