A fluoride shortage in the United States and Canada forced Fort Worth, Texas, to go almost two months without putting any in the public drinking water supply.

The Fort Worth Star-Telegram said the city has found a short-term supplier who delivered the first two shipments of fluoride this week. Fluoride levels were expected to back to normal by Friday.

The shortage is attributed to Hurricane Katrina's disruption of production of the phosphate fertilizers that are the source of most of the fluoride used in drinking water. Rising demand has also tapped out some phosphate mining operations, the newspaper said.

The tight supplies have driven up the cost. The newspaper said Fort Worth paid $560 a ton for the fluoride it received this week, more than twice the normal price.

The American Dental Association said fluoride is credited with reducing tooth decay by as much as 60 percent since World War II.

Copyright 2007 by United Press International