Comparative antimicrobial efficacy of chitosan and a high-potency papain gel (Brix 3000) as endodontic irrigants in deciduous teeth: an in vitro analysis

Abstract

In cases of irreversible pulpitis, root canal treatment is preferred over extraction. The success of endodontic therapy depends on chemical irrigation in addition to mechanical preparation. Sodium hypochlorite, although widely used, has disadvantages, including unpleasant taste and odor and potential toxic effects on periapical tissues and developing permanent tooth germs. Therefore, research on alternative irrigating solutions is ongoing. The aim of this study was to comparatively evaluate the antimicrobial efficacy of chitosan and a high-potency papain-based gel (Brix 3000) compared with sodium hypochlorite in deciduous teeth. In this study, thirty-two extracted anterior deciduous teeth were standardized to a root length of 12 mm, instrumented to size F3, and inoculated with E. faecalis to establish an early-stage colonization model. The specimens were randomly assigned to three experimental groups and positive/negative control subgroups. The experimental groups received 0.2 g/100 mL (0.2% w/v) chitosan solution (prepared in 0.5% v/v acetic acid), 1% (w/v) papain solution prepared from Brix 3000 in distilled water, and 2.5% sodium hypochlorite. The antimicrobial efficacy was assessed in terms of colony-forming units (CFU), and statistical analysis was performed. A p value of < 0.05 was considered statistically significant for all tests. A statistically significant difference was observed among the groups regarding E. faecalis counts ( p < 0.001). The papain group showed significantly higher log₁₀(CFU/mL) values (3.10 ± 1.57) compared with the chitosan (0.11 ± 0.17; p = 0.010), sodium hypochlorite (0.0 ± 0.0; p = 0.008), and negative control (0.0 ± 0.0; p = 0.008) groups. No significant difference was found between the chitosan and sodium hypochlorite groups ( p > 0.05). Within the limitations of this in vitro study, chitosan showed a marked reduction in viable bacterial counts against early-stage E. faecalis colonization in deciduous teeth under the present experimental conditions, whereas the papain-based formulation showed reduced antibacterial performance. However, these findings should not be interpreted as clinical equivalence to sodium hypochlorite. Further studies using mature multispecies biofilm models, clinically relevant irrigation times, and biocompatibility assessments are required before clinical recommendations can be made.