A new study by Australian researchers challenges current dentistry practices, up to the point where they say drilling is old-fashioned. Instead, they say, tooth decay happens so slowly that it can be stopped and reversed before a filling is necessary. According to the researchers, it takes an average 4 to 8 years for tooth decay to move from the outer layers of the tooth to the inner layer. Plenty of time to stop that from happening, is their idea. The new approach should contain several steps, such as advice on how to brush teeth better, restrictions of between meal-snacks and beverages with added sugar, and the application by dentists of high concentration fluoride varnish on teeth showing signs of early decay.