MUNDELEIN, ILDawn Roycroft, a 38-year-old dental hygienist at the Park Court Mall Dental Center, said Monday that she can no longer tolerate the half-truths and outright fabrications she is exposed to hourly. 'Their lips tell of daily flossing, but their gums impart a far different tale,' Roycroft said. 'I became a dental hygienist in order to earn a decent living, clean teeth, and make small talk, not to play confessor to unscrupulous fabulists and prevaricators.' Roycroft asked the public to be candid about their dietary and brushing habits, as denial of unchecked gum-chewing and soda-drinking is 'but a house built on shifting sands.' 