Gingivitis—which may affect more than one-half of the U.S. adult population— is a condition commonly attributed to lapses in basic oral hygiene habits. However, a new study shows that development and reversal of gingivitis at the molecular level is apparently much more complicated than its causes might indicate. Research conducted jointly by the University of North Carolina at Chapel Hill and P&G Oral Care has found that more than 9,000 genes, nearly 30% of the genes found in the human body...