Van Halen's music became less blended and more technical when Sammy Hagar became their singer. He was a better singer than Gonad the Barbarian but his lyrics were cliche driven.
The Chrystal Meth - Nocotine cocktail ass raped EVH. By the end of the 00's, he'd kicked the Meth and his mouth had been surgically repaired. I can't verify if Dental Surgeon: Dr. Nathan Roth did the procedure himself or recommended someone.