Background: Defensins are antimicrobial peptide which classified into two subfamilies, the α-, and β- defensins. Human β defensins 1 (HBD-1), β defensins 2 (HBD-2), β defensins 3 (HBD-3), β defensins (HBD4) and α defensins 1-4 (HNP1-4) have an important role in caries. In the oral cavity, HBD-2 are present in saliva and have antimicrobial activities against oral bacteria, including Streptococcus mutans, a primary etiologic agent of dental caries. This study aimed to determine levels of β defensins 2 (HBD-2) in saliva samples of caries and free caries. Methods: Saliva samples were obtained from 50 students of elementary school were divided into two group: the caries-free group and caries group. The salivary levels of β defensins 2 (HBD-2) in subjects were measured by enzyme-linked immunosorbent assays (ELISA). Results:The average salivary levels of HBD-2 were 266,15 ng/L for the caries-free group and 483,63 ng/L for the caries group respectively. There were significantly difference in the HBD-2 level between patients with caries and patients with free caries (p < 0.05). Conclusion:We conclude that high salivary levels of HBD-2 may represent a biological response of oral tissue to caries. HBD2 can be developed as biomarker to indicate caries and a new tool for caries risk assessment
