Shade changing effectiveness of plasdone and blue covarine-based whitening toothpaste on teeth stained with chlorhexidine and black tea

OBJECTIVE: This study evaluated the effectiveness of toothbrushing with whitening toothpaste in altering the shade of stained human enamel. MATERIALS AND METHODS: Thirty fragments of human enamel, stained with chlorhexidine/black tea underwent 1000 and 5000 brushing cycles (BC) with (n = 10): PLS (Gel Dental Day, Bitufo), Close Up White Now, Unilever (COVB) and regular (Gel Dental Night, Bitufo) toothpaste. Images were taken before staining (baseline), after staining (STN) and following 1000 and 5000 BC and were analyzed using the CIELAB parameters (ΔE, Δb and ΔL). STATISTICAL ANALYSIS USED: Data were submitted to two-way ANOVA (α = 0.05). RESULTS: ΔE was higher from STN to baseline; 1000 BC to STN and 5000 BC to STN (P < 0.001). Significant differences in Δb values were found from 1000 BC to STN and 5000 BC to STN. For COVB, greater ΔL was observed from 1000 BC to STN, what differed statistically from the regular toothpaste (P < 0.05). There was no difference between toothpaste when ΔL was calculated from 5000 CB to STN. CONCLUSIONS: Toothpaste containing COVB or PLS in association with 5000 BCs showed similar effectiveness in changing enamel shade; but after the first 1000 toothbrushing cycles, the use of COVB toothpaste promoted higher lightness in stained enamel.