Toluidine Blue (TB), a dye that belongs to the thiazine family of metachromatic pigments, is only partly soluble in both water and alcohol. To highlight Potentially Malignant Oral Lesions (PML), TB has been employed as a crucial stain. It may also reveal early lesions that a clinical examination might miss. In addition, it can show the complete length of the dysplastic epithelium or carcinoma when excisions are intended, find multicentric or secondary tumours, and aid in the follow-up of oral cancer patients. When choosing the biopsy sample location in PML and getting minimal control of cancer, it is helpful. Lesions stained with TB may show Loss of Heterozygosity (LOH). However, there is disagreement over the clinical interpretation of these variations. TB staining may appear as a Dark Royal Blue or a Pale Royal Blue color. Despite this, the TB test appears to be highly sensitive (97.8-93.5%) but less specific (92.9%-73.3%), mostly due to false positive findings.
