During the past few years, the recent trend of teeth whitening has gained popularity nationwide. These days, it's not just celebrities doing all they can to keep their pearly-whites movie-star bright.

New advancements in dental technology have allowed more people access to teeth-whitening systems like Crest Whitestrips, an at-home teeth-whitening system that uses gel-coated strips to remove dark stains that build up on teeth.

Tonia Elrod, a spokeswoman for Crest products, said she thinks the recent increase in concern about overall health and appearance has caused people to look closely at the condition of their teeth.

"People are paying a lot more attention to their overall health and appearance today," Elrod said. "We say that teeth are your best fashion accessory, and a good smile will do great things for the way you look."

Elrod said people across all age brackets seem to be attracted to Crest Whitestrips.

"In our studies, we see numbers from all over the age spectrum. Whether you're single and in your early 20s looking to make yourself more attractive, or in your 50s trying to renew your overall appearance, people want to make themselves look better," she said. "You can tell just from the number of products that are on the market how diverse the age gap is. It's not just females, but males, too."

Beverly Masullo, office manager at Brian C. White, DDS & Associates, 2590 Park Center Blvd., said their office performs two types of whitening techniques.

One technique is an in-office treatment using a special bleach and lighting system which produces results in the most timely manner.

"Normally with the in-office treatment, your teeth get two or three shades lighter in a matter of a few hours," Masullo said. "Then you go home and we give you trays which you use as a follow-up down the line."

Patients can also choose an at-home system, designed to use custom-fitted trays and a solution made with a lower-concentrated bleach to remove stains during the course of two or three weeks.

Masullo said the at-home system still produces results, but it takes longer to see the difference. At the office where she works, the in-office treatment runs a little over $500, and the at-home treatment costs about $390.

The office first requires an examination, where teeth are cleaned and inspected for problems like regression, cavities and excess tartar buildup.

These things can interfere with the whitening process, and in some cases can increase sensitivity, which is a typical side effect of any teeth-whitening process, Masullo said.

Bill Dempsey (sophomore-biology) is a member of Penn State's Pre-Dental Society.

Demspey said that although bleaching at the dentist's office has faster and better results, the bleach solution can cause greater side effects, such as sensitivity, than a product like Crest Whitestrips because of the concentration.

"Teeth darken because of mineral changes in the structure of the tooth, or by the presence of bacteria he said. "Over time, bleaching removes these layers. However, not all stains can be bleached."

Masullo said drinks like coffee, wine, tea and sodas are most likely to stain teeth. To keep teeth cleaner and whiter, she recommends brushing after meals and flossing to keep stains from building up in between teeth.

Mascullo said although they take longer, over-the-counter products like Crest Whitestrips can still be effective for those who can't afford the clinical procedure.

"We always tell people that they work, but you won't get as high a concentrate or the custom-fitted trays," she said. "So the results you get might not be as thorough as something like the at-home treatment, where the trays are fit specifically for your mouth."