US dentists are reporting an increase in the number of children being treated for cavities and some have aggressive decay. Dr. Jonathan Shenkin, a pediatric dentist from Augusta, Maine, and a spokesman for the American Dental Association, said Devon Koester, age 2 1/2, is one of hundreds of children who needed complex dental treatment that involved two incisors extractions, root canal treatment and a number of fillings and crowns. X-rays showed 11 of Devon\'s 20 teeth had signs of decay when he was admitted to the Center for Pediatric Dentistry at Seattle Children\'s Hospital. Devon\'s mother said she became concerned about her son\'s oral health when she noticed his teeth were discolored at 18 months, but she said she was very busy and supervising Devon brushing his teeth was not a priority. The US Centers for Disease Control and Prevention reported there was an increase five years ago in the number of preschool children with cavities, for the first time in 40 years. Dentists are worried about the number of very young children who require hospital treatment for dental problems, Shenkin said. \"Dentists are particularly worried because many of the children they are seeing have extensive decay, which requires intensive treatment, carried out under general anesthetic,\" Shenkin said in a statement. Shenkin said tooth decay is largely preventable, but most parents he sees were unaware they needed to make sure their children brush their teeth and did not know they need to take children to the dentist at an early age.