Abstract Introduction: In coming years, the WHO has anticipated an increasing number for Oral cancer which has life-threatening consequences. The early recognition and management of oral premalignant disorders can minimize the cancer morbidity. Any oral mucosal abnormality that is associated with a statistically increased risk of developing oral cancer and is estimated that 4.47% of the world’s population may have OPMDs, with the vast majority appearing clinically as leucoplakias. A predominantly white patch or plaque that cannot be characterized clinically or pathologically as any other disorder. Interestingly, not all oral lesions develop into oral cancer, and some oral cancers develop from non-dysplastic lesions. Some morphological alterations are highly susceptible to malignant transformation; for example, in leukoplakia patients, malignancy may arise elsewhere in clinically normal mucosa. Although histologic examination of tissue from a biopsy is the gold standard for diagnosing, chemiluminescence and toluidine blue are principal strategies to conventional examination used to assess the patient’s lesions at risk of malignant transformation. Aim of study: To underline the early detection techniques (toluidine blue and chemiluminescence) and to compare the results through histopathological analysis. Material and methods: A total of 20 patients with clinical appearance of premalignant lesions were included from the outpatients attending Dental clinic Nr. 2, USMF “N. Testemitanu”, Chisinau. Among the subjects, minimum age was 18 years and maximum was 70 years, with a positive tobacco history. The size, location, ease of visibility, border distinctness, and presence of satellite lesions were recorded. All clinical presentations of OPMD disease had been new, with untreated oral mucosal lesions confirmed on provisional, incision biopsy diagnosis. These patients were subjected to conventional oral examination followed by toluidine blue staining and chemiluminescent examination with Microlux DL. After this, a surgical biopsy sample was taken from the suspected lesions for a definitive diagnosis. Results: Chemiluminescence was revealed accurate in visual parameters of the lesions in brightness, sharpness (margin delineation), surface texture and, in some cases, size of lesion, followed by toluidine blue and clinical evaluation. The sensitivity and specificity was more reliable for chemiluminescence (80 and 59.7%) than the toluidine blue (61 and 44.1%). Furthermore a statistically significant association was observed between histopathology results and chemiluminescence results. Of the 35 lesions examined 60% were defined as clinically dysplasia. While 12% were defined as mild dysplasia, 40% moderate, 4% severe dysplasia and 4% carcinoma in situ. The most common was thin leukoplakia with 69% of all cases, continued by thick homogeneous (15%), speckled (7.5%), granular (6.5%) and verrucous (2%) leukoplakia. The floor of the mouth was the most frequently involved site (42.5%) , followed by the lateral tongue (31.5%) followed by buccal mucosa (23%), the gingiva (3%). The gender ratio among the patients, were men (82%), over the age of 60 years (65%). DIGITAL TECHNOLOGIES IN MULTIDISCIPLINARY DENTISTRY – September 9-10, 2023 37 Conclusions: Chemiluminescent light and staining with toluidine blue can be used as a general oral mucosal examination system and may in particular improve the visualization of potentially premalignant lesions. Although it is an easy, safe, minimal time consuming, and noninvasive protocol, it has only adjunctive utility and it does not replace biopsy for the diagnosis of leukoplakia. Key words: leukoplakia, screening, chemiluminescence, toluidine blue.