Composition Of Extrinsic Black Tooth Stain Extract From Primary Dentition

To investigate the composition of extrinsic black tooth stain (EBS) extract from deciduous teeth, and to clarify its association with melanin. EBS samples from primary tooth were collected and extracted using the alkali dissolution and acid precipitation method. The basic properties of the extracts were studied. The EDS, UV-Vis, FTIR, and Py-GC-MS were used to characterize their components. Two EBS extracts were obtained (EBS-1 and EBS-2). EBS-1 was insoluble in water, HCl/NaOH solution, common organic solvents nor FeCl3 solution. EBS-1 might contained hydroxyl, amino, methyl, methylene, aromatic C=C and carbonyl group, ether and iron-oxygen coordination bond. The main pyrolysis products of EBS-1 were esters (26.29%), acids (18.37%) and etc. EBS-2 was insoluble in water, HCl solution, nor organic solvents but soluble in NaOH solution, reacted with FeCl3. UV-Vis results showed its maximum absorption peak was at 291nm, with an absorption slope of -0.0023. EBS-2 might contained hydroxyl group, amino, methyl, methylene, aromatic C=C and carbonyl group, ether and iron-oxygen coordination bond. The main pyrolysis products of EBS-2 were carbon dioxide (36.54%), hydrocarbons (20.28%), ketones (14.81%) and etc. Both of the extracts contained C, O, N, Fe, S and H elements. EBS extract comprised EBS-1 and EBS-2. EBS-1 might contained Maillard reaction products, while EBS-2 was hypothesized to be a complex with esters, carboxylic acids, cyclic ketones, phenolic hydroxyl substance and melanin.