Efron and Hudgens, 30, met on the 2005 set of the first High School Musical and stuck together after they blew up with the movie's success. They went on to date for several years before breaking up in 2010.
"It was a good thing," Hudgens said of the relationship in a 2011 Shape interview. "The relationship kept me grounded, and because I was with someone who knew me so well, I didn't need to try to be someone I'm not … Long-distance relationships are hard no matter what. When you don't have face-to-face time, it's just different. Having an iPhone helped, but it just wasn't the same."
But by the time 2017 rolled around, Hudgens admitted that she and Efron were no longer in contact.
"No, I completely lost contact with him," Hudgens told Access Hollywood after being asked if they still talked.
The actor dated model Sami Miró, 31, for almost two year before breaking up in April 2016. Although they kept their relationship private, they were frequently spotted out together and Efron even posted a few pictures of her on his Instagram, which he quickly deleted after their split.
Efron was linked to his Baywatch costar Alexandra Daddario, 32, when the movie premiered in 2017, though the two maintained they were friends. They were later seen on dog toy shopping with their pups in August 2018, fueling the rumors again.