Can "Good Bacterium" cure dental caries?

Dr. Jeffrey Hillman is the creator of BCS3-L1, a genetically altered strain of the Streptococcus bacteria and contender in the dental caries vaccine race.   BCS3-L1 does not produce enamel-eroding lactic acid and upon introduction to the subject's mouth, would replace the native Streptococcus. 

Hillman has published research demonstrating the safety and effectiveness of the treatment in lab rats.  BCS3-L1 is currently undergoing clinical testing by the FDA.   If approved, Hillman says the treatment would probably cost less than $100 and be administered as an oral agent in a dentists office.