Background: In order to identify the different reasons related to the late diagnosis of oral cancer, several studies have sought to qualify and evaluate the knowledge, attitudes, and practices (KAP) of primary health care professionals regarding the detection of oral cancer. However, it is observed that a large part of these studies do not include the implementation and evaluation of educational interventions focused on the diagnosis of oral cancer. Objectives: The objective of this study was to diagnose the provision of services in Primary Health Care (PHC), to qualify dentists, and to evaluate the impact of this intervention on professional knowledge, attitudes, and practices (KAP) for the early detection of oral cancer in Espírito Santo, Brazil. Methods: This is an intervention study in which questionnaires were applied to evaluate the KAP of professionals in the pre-training period (stage I) and post-training period (stage II). The situational diagnosis of PHC was developed based on a structured questionnaire and secondary data from hospital cancer registries (2017-2022). Between 2019 and 2022, 7 training workshops involving 708 dentists were conducted. Descriptive and inferential statistical analysis, including knowledge assessment using a Likert scale, analysis of diagnosis in clinical vignettes using ROC curves, and analysis of the association between the indication and performance of biopsies in the pre- and post-training periods, were performed, adopting a significance level of p < 0,05. Results: The availability of biopsies and anatomopathology by municipalities increased from 31% and 49%, respectively, in 2018, to 42% and 44% in 2022, with a significant increase in the availability of biopsies in the Metropolitan region (p=0.0496). The average time for issuing the histopathological report ranged from 15 to 30 days in 35% of municipalities in 2018 and fell to 28% in 2022. Actions for the prevention and early detection of oral cancer were promoted in 45% of municipalities, despite the predominance of disease diagnosed at an advanced stage (58.6%). A significant improvement was observed in the recognition of oral cancer (97.7%) and potentially malignant disorders (91.9%). There was a significant increase in the biopsy indication for the diagnosis of oral cancer and potentially malignant disorders between pre and post-training, as well as in the performance of the procedure by the professionals themselves (p < 0.001). Conclusions/Implications for practice or policy: The situational diagnosis of primary health care showed the need to implement strategies to expand diagnostic services and encourage the promotion of actions for the prevention and early detection of oral cancer, reinforcing the importance of training dentists as a strategy to strengthen the early detection of oral cancer in primary health care, aiming to expand the knowledge and diagnostic confidence of professionals.

Spatial distribution of new cases of oral cancer diagnosed in Espírito Santo from 2017 to 2022, according to data obtained from the RHC of HSRC-AFECC and HECI.