"Leave 'Em Laughing is a 1928 two-reel silent film starring Stan Laurel and Oliver Hardy. Produced by the Hal Roach Studios, it was shot in October 1927 and released January 28, 1928 by Metro-Goldwyn-Mayer."

https://en.wikipedia.org/wiki/Leave_%27Em_Laughing

"In the dead of night, a terrible toothache wakes up poor Stan, and after a series of home-made remedies, Ollie takes him to the dentist. There, ample amounts of laughing gas lead to the perfect mess. Will Stan ever visit the dentist again?"

https://www.imdb.com/title/tt0019079/

https://archive.org/details/laurel-and-hardy-leave-em-laughing-silent