The Role of Toluidine Blue Vital Staining in the Diagnosis of Oral Mucosal Lesions in Dental Practice: A Narrative Review.

Oral cancer imposes a disproportionate global health burden, with persistently poor survival rates primarily attributable to late-stage diagnosis. oral potentially malignant disorders (OPMDs) are identifiable and clinically actionable precursors to the development of most oral squamous cell carcinomas (OSCCs). However, accurate risk stratification in routine dental practice remains a challenge. Toluidine blue (TB) vital staining, a cationic, acidophilic, metachromatic dye with selective affinity for nucleic acid-rich dysplastic and malignant epithelium, has been employed as a chairside adjunctive diagnostic tool for more than four decades. This narrative review synthesizes the current evidence on the mechanism of TB staining, its diagnostic accuracy, and its utility within the broader landscape of adjunctive tools available to dental practitioners. TB demonstrates a pooled sensitivity of 71% to 95% and specificity of 68% to 81%, with its diagnostic odds ratio consistently exceeding that of clinical visual examination. Compared with light-based adjunctive tools, TB exhibits superior specificity to chemiluminescence and autofluorescence, although its sensitivity is lower than that of both techniques. The integration of TB into a multimodal diagnostic protocol, combining clinical examination, staining, and, where indicated, histopathological confirmation, optimizes the detection of high-risk lesions, guides biopsy site selection, and supports surgical-margin assessment. Known limitations include false positives from inflammatory conditions, false negatives in hyperkeratotic lesions, and operator-dependent interpretation. Emerging technologies, such as reflection spectroscopy, artificial intelligence-assisted image analysis, and combined multimodal platforms, offer potential solutions to address these constraints. Dental practitioners who incorporate TB into a structured clinical workflow, interpreted alongside the full clinical picture, are well positioned to improve early detection and reduce diagnostic delay, which remains a major determinant of oral cancer mortality.