DEFB1 and periodontitis: Given the positive role of phase I periodontal therapy (mostly SRP) in treating periodontitis17 and the existing debates about the differences in hBD-1 levels in patients with periodontitis versus those with healthy periodontium,3,10,20,21 this study aimed to evaluate the effect of phase I periodontal treatment on the salivary levels of hBD-1 in patients with periodontitis before and after phase I periodontal therapy.