The Houston Astros will soon have the most sparkling smiles in baseball. Grammy-nominated Houston rapper Paul Wall has offered free grillz - precious metal covers worn over teeth - to every member of the team to congratulate them for reaching the World Series against the Los Angeles Dodgers. Wall made the offer on social media Sunday , a day after the Astros beat the New York Yankees to capture the American League championship and advance to the second World Series in franchise history.