An induced extrinsic tooth stain prevention model to investigate whitening potential of sugar-free chewing gums

摘要

Purpose: To establish an accelerated clinical test method to evaluate the effectiveness of sugar-free gums in prevention of the formation of extrinsic stains when chewed over a 2-week period in conjunction with daily tooth brushing. A secondary objective was to compare three methods for measuring extrinsic stain. Methods: 25 healthy adult volunteers were enrolled in a single center, examiner blind, randomized 4-way crossover clinical study. Starting with a stain-free baseline, subjects rinsed five times daily with freshly brewed black tea, followed either by chewing one of three different gums for 12 minutes or not chewing (negative control). Extrinsic stain was measured at 1 and 2 weeks by modified Lobene Stain Index (MLSI), digital imaging, and a Vita EasyShade spectrophotometer. Results: At 2 weeks, MLSI scores showed a statistically significant mean reduction of 43% or greater versus no-gum control for all three gum treatments. Digital image analysis and Vita EasyShade measurement showed reductions of yellowness (measured by difference in Delta b* values between the three gums and the non-gum control treatment) ranging from 0.28 to 0.34 and 3.52 to 4.18 Delta b* units, respectively, for subjects using the chewing gums versus no-gum control (P 0.05) after 2 weeks. This clinical study demonstrated that sugar-free gum can effectively reduce new stain formation along with daily tooth brushing in as little as 2 weeks when used in conjunction with tea rinsing to help promote more rapid stain formation. All three test methods confirmed the results, albeit with different levels of statistical significance. A minor modification of gum base polymer, or change of flavors, did not significantly impact the prevention of new stain formation.