The treatment of stained teeth has been one of the striking aspects of stomatology and esthetic dentistry. Based on detailed data and references, this article introduces the types of stained teeth and the main treatment methods including strong point, weakness, limitation of the usage, result, and the relevant mechanisms. It addresses the researches on problems in the treatment of stained teeth. Also in this paper is envisaged what will be done to treat the stained teeth in future.
Dental Veneers ; Humans ; Tooth Bleaching ; Tooth Discoloration ; etiology ; therapy

OBJECTIVETo investigate the mechanism of discoloration and the efficacy of bleaching in non-infected traumatically discolored teeth.

METHODSIn vitro model of discolored teeth: sample of fresh erythrocytes was placed in the pulp cavity of 20 extracted teeth and centrifuged for 3 consecutive days. These discolored teeth were divided equally and randomly into two groups: group A (control group); group B (bleaching group), bleached with 10% carbamide peroxide gel for 4 weeks. And then all teeth were prepared for histological examination and subjected to a series of histochemical tests to analyze some of the biochemical changes following haemorrhage into the pulp chamber and post-bleaching.

RESULTSHaemoglobin and haematin were detected in the dentinal tubules of discolored teeth from group A and no evidence of ferric or haemosiderin. Specimens from group B demonstrated a negative response to histochemical tests.

CONCLUSIONSIn the absence of bacterial invasive, haemoglobin and haematin could cause discoloration of non-infected traumatized teeth. Peroxide bleaching agent can effectively remove haemoglobin and haematin.

Adolescent ; Child ; Humans ; In Vitro Techniques ; Random Allocation ; Tooth Bleaching ; methods ; Tooth Discoloration ; etiology ; therapy

OBJECTIVE: To determine the optimum staining condition of tea solutions on bovine incisors in vitro, by comparing the color stability of tooth surface of different concentrations of tea solutions and methods on bovine incisors in vitro. METHODS: Twenty bovine incisors with color surface A1 were chosen, then randomly divided into 4 groups (n=10). Group 1: soaked with 2% tea solution continuously for 6 days; group 2: soaked with 2% tea solution for 6 days, but changed fresh tea solution everyday; group 3: soaked with 1% tea solution continuously for 6 days; group 4: soaked with 1% tea solution for 6 days but fresh tea solution changed every day. After 6 days of staining, the surface color (Δ E value) of all the samples were measured with crystal eye. After brushing 30 times with toothbrushes, the color of bovine incisors were measured again. Then the samples were soaked in artificial saliva at 37 ° C, and Δ E value was measured for 14 days. RESULTS: After staining for 6 days, the Δ E values of the 2% tea solution groups were better than those of the 1% groups (20.21 vs. 16.44, 24.09 vs. 19.22, P<0.05); the groups with the same tea solution concentration, a better result was observed for the group soaked with daily fresh tea solution than for the group that experienced continuous staining (24.09 vs. 20.21, 19.22 vs. 16.44, P<0.05). Groups 1 and 2 were selected for subsequent brushing experiments. The color of both groups became lighter after brushing, and a better result was observed for the continuous staining group than for the group stained in daily fresh solution (3.06 vs. 9.51, P<0.05). The samples with better coloring effect soaked with 2% tea solution continuously for 6 days were put into artificial saliva for 14 days. There was not any significant change in coloring at the end of the first two days (1.51 vs. 1.51, P>0.05), and the color was visibly lighter after the third day (1.51 vs. 5.89, P<0.05), and no further significant change was observed until the 14th day (5.81 vs.5.89, P>0.05), which was darker coloring than that of the pre-staining group. CONCLUSION Continuous staining on bovine incisors with 2% tea solution with subsequent soaking in artificial saliva resulted in consistent coloring from day 3 to day 14, and this method could be used as an ideal model for teeth staining in vitro.
Animals ; Cattle ; Color ; Incisor ; Materials Testing ; Staining and Labeling ; Tea/adverse effects* ; Tooth Discoloration/etiology*