NEW ORLEANS - A Louisiana researcher has a $2.5 million, five-year federal grant to develop better materials for dental fillings.

LSU Health New Orleans says the National Institute of Dental and Craniofacial Health wants professor Xiaoming Xu to create stronger, longer-lasting materials that can also fight bacteria, warding off repeat cavities.

A news release says 60 percent of all dental operations are filling replacements, because the materials last five to seven years.

Xu says bacterial biofilms at the edges of fillings are a leading cause of secondary cavities. He says another is that the filling weakens and breaks.

Biofilms on teeth are called dental plaque. It contains different kinds of bacteria that stick together and excrete a protective barrier.

Xu is the school's director of biomaterials research.