['Recent studies suggest that stress can predispose an individual to the development of periodontal disease, but the exact biological mechanism is unknown. Considering that psychological stress can down-regulate the production of β-defensins (antimicrobial peptides produced in the oral cavity), the aim of the present study was to evaluate the association between stress and salivary levels of β-defensin 2 (HBD-2) and β-defensin 3 (HBD-3).', 'For this purpose, seventy five volunteers, classified as periodontally healthy, were submitted to a psychological evaluation using a validated questionnaire (Questionnaire of Lipp-ISS). Following analysis of the questionnaires, the subjects were divided in two groups (Group A: Absence of stress and Group B: Presence of stress). Unstimulated saliva samples were collected and the concentration of total protein was determined using the BCA method, and the concentrations of HBD-2 and HBD-3 were determined by ELISA.', 'The levels of total protein did not show a statistically significant difference between the groups. Analyses of HBD-2 and HBD-3 concentrations indicate that the stress condition was not associated with the levels of either peptide in saliva (P=0.3664 for HBD-2 and P=0.3608 for HBD-3).'] Does psychological stress have no association with salivary levels of β-defensin 2 and β-defensin 3?