Effects of demineralizing tetracycline-stained human dentine

In view of the belief that tetracycline is removed from bone when it is demineralized, it was decided to investigate the effect of demineralizing agents on human dentine. Teeth which had been stained in vivo with tetracycline were fixed in formalin and demineralized using mineral and organic acids and EDTA at neutral pH. When examined microscopically under ultraviolet light, the tetracycline lines in dentine, although reduced in intensity, were all still present. This indicates that formalin fixation does not appreciably alter the fluorescent effect of tetracycline in teeth and that it is not removed by demineralization. It seems likely therefore that tetracycline is incorporated in both the mineral and organic phases of human dentine.