Researchers Jose Cordova and Erich Astudillo have discovered a new molecule  that kills the bacteria Streptococcus Mutans, long known to be responsible for breaking down sugars in food in the mouth, which damages tooth leading to decay . The new molecule they call "Keep 32" has been found to kill the bacteria. The two have applied for a patent  on their discovery and have also begun a marketing strategy aimed at both oral care products and food products. They say either product, if left in the mouth for just 60 seconds ,will kill all the harmful bacteria in the mouth and keep _ at bay for several hours. If the new molecule passes health and safety tests, the two believe products using their new molecule should be on the market in as little as a year and a half. They expect the market for such a product to reach $300 million in just the first year. The two have been working together since 2005 using money from the Founder Institute and say the aim is to approve the process for creating the molecule they've discovered for big companies like Procter & Gamble, Colgate even candy companies such as Hershey's. In interviews, Astudillo has suggested that the two researchers are already heavily into discussion with several companies, some of which are interested in buying the patent once it is approved. Over the years many products have _ with announcement of reducing tooth decay and even the loss of teeth, but other than the introduction of fluoride  into drinking water, not much progress has been made. If the announcement made by this new team proves true however, it could foresee a mark in saving the world of tooth decay as well as helping to improve the health for millions of people as tooth decay has been linked to many other health problems throughout the body including heart attacks. The phrase "come on the scene" in Para. 4 is closest in meaning to   _  .
performed occurred existed arrived