Effectiveness of whitening mouthwashes on tooth color: an in vitro study.

Products for tooth whitening (or tooth color maintenance) that improve smile esthetics have become increasingly popular due to their easy accessibility and low cost. This in vitro study assessed the effect of whitening mouthwash on bovine tooth color. Forty-eight bovine teeth were divided into 3 immersion groups: SL, artificial saliva (control); CLW, Colgate Luminous White; and OBW, Oral-B 3D White. After prophylaxis with pumice, the initial color was measured using the CIE L*a*b* system. Teeth were immersed in the solutions for 2 minutes, 3 times per day, for 30 days. Changes in color (DeltaE*, DeltaL*, Deltaa*, and Deltab*) were measured at days 14 and 30. Data were analyzed with 2-way analysis of variance and Tukey test (P < 0.05). At day 30, values of DeltaE* had significantly decreased in group SL and increased in group OBW; in addition, at day 30, the DeltaE*values in group CLW were significantly greater than those in group SL. The DeltaL* values for groups SL and OBW significantly decreased from day 14 to day 30. At day 30, the Deltaa* and Deltab* values were lower in all 3 groups. The results showed that the whitening mouthwashes did not improve color after 14 and 30 days.