Antibiofilm Activity and Cytocompatibility of Novel Enzymatic Root Canal Irrigants

There is a need for safe and potent antibiofilm agents for root canal irrigation. The aim of this study was to investigate the antibiofilm activity of enzymatic irrigants (Bromelain and Papain) and their cytocompatibility to mammalian cells.

Biofilms of Enterococcus faecalis were developed on dentin discs and treated with 0.05% bromelain, 4% papain, 2.5% sodium hypochlorite (NaOCl) or saline for 15 min. The antibiofilm effectiveness was characterized by quantifying the colony forming units (CFU) and confocal microscopic examination of the bacterial cells (live/dead staining) and extracellular matrix polysaccharide using a selective fluorophore binding assay. Cytotoxicity of 0.05% bromelain, 4% papain and 2.5% NaOCl to human periodontal ligament fibroblasts was investigated using a metabolic activity assay. Data were analyzed using analysis of variance and nonparametric tests, with significance set at P < .05.

Papain (4%) and Bromelain (0.05%) demonstrated 5 log CFU reduction, which was comparable to 2.5% NaOCl (P > .05). Confocal microscopy further confirmed that bromelain, sodium hypochlorite, and papain caused significantly greater bacterial cell death compared to saline (P < .05). Papain significantly reduced the extracellular matrix polysaccharide content within the biofilm compared to all other groups (P < .05).

This study demonstrated that bromelain and papain showed comparable antibiofilm activity as 2.5% NaOCl and were more biocompatible than NaOCl, highlighting their potential to be developed as root canal irrigants.