Comparison of bleaching effect on discolored teeth by different beverages: an in vitro study

Abstract

Background: Tooth bleaching is an effective method to remove both endogenous and exogenous stains. This study aims to evaluate and compare the bleaching efficacy of tea, coffee and cola stains on teeth. Materials and Methods: 30 bovine tooth samples were divided into three groups: tea, coffee and cola (n = 10/group). Staining was obtained by soaking the tooth samples for 3 weeks in each drinks. Before bleaching, tooth samples were polished with fine pumice powder and slow-speed handpiece for 10 seconds, speed of 2500 rpm. The bleaching process was performed with 10% carbamide peroxide for 14 days, 8 hours/day. The effectiveness of the bleaching process is evaluated through the change in the brightness (L*), saturation (a*, b*) values and the total color change (DE*) of the CIELAB system with Crystaleye spectrocolorimeter. Results: After bleaching process, all three stained groups showed the color changes in the following direction: increase L*, decrease a*, decrease b*. The polishing phase could remove part of the staining and the whitening phase achieved the fastest bleaching effect after 1 week. The tea group achieved a greater color change than the cola group during all phases and greater than the coffee group at the polishing phase (p<0.05). Conclusions: The polishing phase is effective in removing the exogenous stains on teeth due to beverage consumption. The bleaching efficacy between the teeth stained with tea, coffee and cola is different, in which the teeth stained with tea have a higher whitening effect. Key words: tea, coffee, cola, extrinsic stain, bleaching