Lowenberg is a cosmetic dentist and partner at Lowenberg and Lituchy in New York City. His clients include Courtney Cox and Amanda Peet.

A great smile can improve your entire appearance by making you look younger and feel more confident. Here's how to make yours stand out.

Get in the habit. You can't have good teeth if you don't brush and floss twice a day. Focus on the gum line, where plaque lingers, and try a whitening toothpaste to remove stains. I also recommend professional cleanings every three to four months to reduce plaque and prevent tooth decay.

Bright ideas. For whiter teeth, a drug store bleaching kit may do the job. If not, book an office treatment, which whitens with a higher concentration of hydrogen peroxide and costs about $500. Afterward, cut back on coffee, red wine, and dark sodas. Or drink them with foods so they are less likely to leave a yellowing residue.

Material concerns. It's very common to replace silver fillings with porcelain ones now. Besides the aesthetic concerns, the metal may raise mercury levels. For gaps or spaces between teeth, consider cosmetic bonding; it adds a thin layer of white composite