and helps prevent cavities. go beyond brushing with act®. you never know what you might find digging underneath rome. well, how about this one? while digging rome s third metro line, archaeologists found a third century house destroyed by fire but well-preserved. so cool. complete with central heating systems, beams and even the bones of a dog. cnn s ben wedeman takes a step back in time with this report. reporter: scratch the surface in rome and you find history. it s an archaeologist s paradise. but for officials overseeing the long, delayed construction to the city s newest subway line, line c, rome s embarrassment of ancient riches is a curse that keeps on giving. while digging a shaft for the subway s tunnel near the coliseum late last year, workers