RESUMO
Background and Objectives: In vivo stains are prompt resources, which have emerged, in the recent years, to aid as clinical diagnostic tools in detecting early premalignant and malignant lesions. The aim of the study was to determine the diagnostic efficiency of toluidine blue with Lugol's iodine in oral premalignancies and malignancies and to evaluate the reliability of in vivo staining with toluidine blue and Lugol's iodine in the lesions at risk of malignancy. Materials and Methods: The study group comprised 30 subjects with clinically suspicious premalignant lesions and 30 subjects with clinically suspicious malignant lesions. All the lesions were stained consecutively with toluidine blue and Lugol's iodine and the dye retention were recorded with photographs. Depending on the retention of the dyes, the biopsy site was determined. The biopsy specimens were sent for histological confirmation and results were statistically analyzed. Results: The overall diagnostic accuracy of Lugol's iodine when used consecutively with toluidine blue stain in distinguishing premalignant lesions and malignant lesions was 90%. As the degree of differentiation of malignant lesions progressed toward more severity, they failed to show the retention of Lugol's iodine and the result was highly significant statistically, with a P value < 0.001. Interpretation and Conclusion: Lugol's iodine when used with toluidine blue helped in delineating the inflammatory lesions and was the mean source in determining clinically the degrees of differentiation of malignant lesions as the poorly differentiated malignant lesions without glycogen content failed to show Lugol's iodine retention. Toluidine blue with Lugol's iodine can be used as a pretherapeutic assessment of the biologic aggressiveness of the disease.