Journal Watch – Effect of pomegranate solution alone or combined with chlorhexidine against oral multispecies biofilm

Journal Article

Effect of pomegranate solution alone or combined with chlorhexidine against oral multispecies biofilm

J. A. Gallas, L. L. Pelozo, S. A. M. Corona, Y. Shen, M. Haapasalo, M. D. Sousa-Neto, A. E. Souza-Gabriel

The never-ending search for killer irrigants in root canals continues. Usually, it is some instantly forgettable, unfathomable chemical with a name like n-quanternary bis-bi-phenalamine.  Here, I rather like the fact that these researchers have stumbled on the humble pomegranate to do a good job of our root canal cleaning. 

So much more enticing and flavoursome I think. As a regular hypochlorite ‘leaker’, with patients retching over the mouthful of bleach I have deposited in their mouth while using the laser, I will look forward to expressions of pleasure as the pomegranate juice slips down their throats.

This was an in-vitro study in which a multi-species biofilm was exposed to different concentrations of Punica granatum extract (PGE) from (Brazilian) pomegranates, which were measured for their killing ability. Chlorohexidine (CHX) was then added to the highest concentration of PGE to see whether its killing action is enhanced.

The background here is the general toxicity and unsuitability of sodium hypochlorite in the mouth. The trouble is that there seems no beating its bactericidal action, as well as its role as an organic tissue solvent. Mixtures of less toxic irrigants could form a synergistic alternative to sodium hypochlorite.

The conclusion was that the 30% PGE (alone or combined with CHX) exhibited a greater antibiofilm effect on oral multispecies biofilms grown on hydroxyapatite discs than 2% CHX alone.

Digging into the results, the bacterial kill rate for 30% PGE was 37%–53% and similar to CHX. It seems there was no synergistic action combining the two. I have to say that the percentage kill rate seems somewhat disappointing.  I would like to think that any disinfecting irrigants I use are doing better than a 40% kill rate.  The problem is that there is no comparison to the gold standard. What is the kill rate for hypochlorite using these discs?  Surely this needs to be in the discussion. 

International Endodontic Journal. First published: 10 August 2024
https://doi.org/10.1111/iej.14135