The Insider.com

Julia Roberts is known for her signature megawatt smile, and she recently revealed the secret to her sparkling set of teeth -- brushing them with baking soda.

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"I brush [my teeth] with baking soda," she tells InStyle in the magazine's September issue. "[My grandfather] would put a big heaping mound of it on his toothbrush. He had only one cavity in his entire life."

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"Sometimes that's all I do as far as a regimen goes," she adds, citing her lack of personal time due to her three kids, twins Hazel Patricia and Phinnaeus "Finn" Walter, 7, and Henry Daniel, 5. "When you're dressing three people besides yourself, something has to fall away. I've learned to always have a big pair of dark sunglasses within arm's reach before going out."

But would she ever get Botox or plastic surgery to maintain her looks?

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According to the Pretty Woman, not at this point.

"For me, at this point, I'm clinging to my good genes and lots of hugs and kisses from my husband," she says. Though she does stop short at taking digs at other actresses fond of the Botox needle (ahem, Nicole Kidman). "I'm pro whatever works for you," she says diplomatically.