One of the most memorable phrases from one of Madonna's biggest hits is: "We are living in a material world / And I am a material girl." In this case, Madge is a material grill.

The singer, who turned 55 on Aug. 16, flashed a golden grin via a grill at her Hard Candy Fitness outpost in Rome earlier this week. She has worn the grill before, posting the pics on Instagram. See 'em below.

Even at 55, Her Madjesty has no qualms about flashing a 24 karat smile, since there is no way that thing wasn't custom-made, with an accompanying hefty price.

Are grills better left for starlets like Rihanna or grill fan Lil Wayne? Is Madonna too "brace faced?" Or can Madge rock this increasingly popular look. Tooth accessories... we dunno. Maybe it's best to leave chompers alone.

See previous pics of her rocking the same grills.