Abstract: Objective: To analyze and compare the staining effects of four tea models on isolated bovine incisors. Methods: Thirty-two fresh bovine mandibular incisors were randomly divided into 4 groups: A, B, C and D. Each group of cattle incisors was divided into two sub groups after cleaning and excision. They were divided into subgroup 1 and subgroup 2. The tea solution of 0.5%, 1%, 2% and 4% was made with Pu'er cooked tea. A1, B1, C1, D1 components were soaked in different concentrations of tea solution in continuous immersion dyeing for 7 days, and A2, B2, C2 and D2 groups were immersed in fresh tea with different concentrations daily to soak and dye for 7 days. The △E^* value of bovine incisors was measured before and after dyeing, and the changes of △E^* values were observed again after brushing and artificial saliva fixation. Results: The dyeing effects of the tea solution in groups C and D were better than those in group A and B (P<0.05), and those of subunit 2 were better than those of subunit 1. After brushing experiments, the staining effects of C1 and D1 groups were better than those of the C2 and D2 groups (P<0.05). C1 and D1 specimens with good staining effect after brushing were soaked in artificial saliva for 1 to 5 days. Compared with that before soaking, the two groups were more stable when artificial saliva was soaked for 1 to 2 days. Conclusion: When tea-stained isolated bovine incisor model was established, a good staining effect could be obtained by continuously immersing in 2% or 4% tea solution for 7 days. The established dental staining model is recommended to be preserved in artificial saliva for 1-2 days to ensure its color stability.

Key words: Isolated bovine incisor, Tea solution, Dyeing concentration, Dyeing method, Effect