Research in Focus
Dental Student's Study Finds White Wine Can Make Tooth Stains Darker

Ms. Cristina Dobrescu, Class of 2010

Every summer, dozens of NYU dental students live the life of a scientist, conducting research to gain a deeper understanding of the science behind the oral health conditions they will be treating as dentists.

One such student, Cristina Dobrescu, Class of 2010, spent part of the summer of 2008 conducting a study to determine why people who drink white wine are more likely to develop tooth stains than those who do not.

"I never used to give much thought to research," Ms. Dobrescu recalls, "but when I took Diagnosis and Treatment of Oral Diseases, a course dealing with issues such as tooth staining, dental caries, and periodontal disease, one of my instructors, Dr. Mark Wolff, told me that conducting research was an excellent way to learn more about some of the topics covered in the course while developing skills that will be useful to me as a practicing dentist."

"Being involved in research gives students an in-depth appreciation for science, for scientific methodology, and for comprehending what does and does not constitute valid scientific evidence," says Dr. Wolff, who is Professor and Chairman of the Department of Cariology & Comprehensive Care and Associate Dean for Predoctoral Clinical Education at the College of Dentistry. "By becoming familiar with these concepts, the student will be able to acquire and assimilate new knowledge and adapt to future changes in practice and in the profession."

"Tooth staining is a common problem treated by dentists," added Dr. Wolff, who developed the wine study research protocol with Ms. Dobrescu and was a coinvestigator on the study. "Although it has long been known that red wine causes teeth to stain, we wondered why people who drink white wine also develop dark spots on their teeth."

According to Ms. Dobrescu's study, drinking white wine can increase the potential for teeth to take on dark stains because the acids in white wine create rough spots and grooves that enable chemicals in other beverages, such as coffee and tea, that also cause staining, to penetrate deeper into the tooth. Ms. Dobrescu submitted an abstract describing her findings to the International Association for Dental Research, which accepted it for presentation at its 2009 annual scientific meeting in Miami. Ms. Dobrescu presented the findings on April 1, the opening day of the conference. A program that aired recently on Food Network TV also featured findings from her study.

Ms. Dobrescu compared two sets of six cow teeth, whose surface closely resembles that of human teeth, and used a spectrophotometer, an instrument that measures color intensities, to evaluate staining levels.

She found that teeth soaked for one hour in white wine before being immersed in black tea had significantly darker stains than teeth immersed for one hour in water before exposure to the tea. According to Ms. Dobrescu, dipping teeth in white wine for one hour is similar to the effect of sipping the wine with dinner.

Still, red wine continues to beat out white wine when it comes to staining teeth. When Ms. Dobrescu repeated the experiment with red wine, the resulting stains were significantly darker than those in the white wine group. "Red wine, unlike white, contains a highly pigmented substance known as chromogen," she explained.

But she and Dr. Wolff note that connoisseurs concerned about staining need not cut back on their consumption. "The best way to prevent staining caused by wine, as well as other beverages, is to use a toothpaste containing a whitening agent," they advise.

Dr. Denise Estafan, an Associate Professor of Cariology & Comprehensive Care, was a coinvestigator on the study.