Efficacy of Antimicrobial Peptide GH12 on a Multispecies Endodontic Biofilm Model: An In-vitro Study

This study aimed to evaluate the antibacterial efficacy of different concentrations of GH12 on a simulated multispecies biofilm comprising Enterococcus faecalis, Streptococcus mutans, Fusobacterium nucleatum and Porphyromonas gingivalis.

Single rooted teeth were decoronated, cut into 1.5 mm sections to obtain dentine discs which were randomly allocated into five groups: (n=12 each), Group 1: Phosphate Buffered Solution (PBS) - negative control, Group II: 5% Sodium hypochlorite (NaOCl) - positive control, Group III: Minimum Inhibitory Concentration (MIC) of GH12, Group IV: 2x MIC of GH12, Group V: 4x MIC of GH12. Colony forming units, Crystal violet assay and scanning electron microscopy examinations were performed. One-way ANOVA and Turkey's test were applied for statistical analysis using the SPSS software version 22.0.

Group II (NaOCl) showed maximum reduction in bacterial load followed by Group V (GH12 16mg/mL) with no statistically significant difference (p=1.000). On comparing the mean CFU reduction, the maximum reduction was identified for S. mutans and the least was for P. gingivalis. There was marked erosion observed in the NaOCl group whereas the GH12 group showed no erosive changes in the morphology and no bacterial colonies was identified.

The findings revealed that GH12 at higher concentrations inhibits and disrupts the growth of multispecies endodontic biofilm comparable to NaOCl but without erosive effects to the dentine, further highlighting its potential to be used as an antimicrobial solution. (EEJ-2023-10-147).