Effect of Chlorhexidine digluconate on endodontic sealers

A recent study showed increased antimicrobial activity of three endodontic sealers after chlorhexidine contact. Cell toxicity and physicochemical properties were mostly negatively affected.

Chlorhexidine (CHX) is used as root canal irrigation solution, especially as last irrigant, and may potentially interact with sealers and affect their physicochemical and biological properties. The study aimed to assess such properties of AH Plus, BioRoot RCS and Pulp Canal Sealer (PCS) after contact with CHX.

– A multidisciplinary team consisting of Vasilis Kapralos and Andreas Koutroulis from the University of Oslo, Håkon Valen of NIOM and FHI, among others, cooperated on the study, says NIOM-engineer Else Morisbak.

The study

The sealers were in contact with CHX for one minute. For investigating biological properties (antibacterial activity and cytotoxicity), leachates were formed in saline of freshly mixed, 1-, 7- and 28 days set sealers.

Cytotoxicity was assessed as number of surviving cultured cells after exposure to the leachates. Antibacterial properties of sealer leachates were investigated for planktonic and biofilm growth of E. faecalis, S. mutans, S.epidermidis and S.aureus.

The physical properties (water uptake, sorption, solubility, porosity, surface characteristics) of sealers and the pH of the immersion liquid were also assessed over a 28-days period

Results

– We found that CHX improved the antibacterial properties of the sealer leachates but increased cell toxicity for all sealer leachates, except for freshly mixed PCS, Morisbak says.

Other findings included how BioRoot RCS leachates presented the highest antibacterial properties and cell viability both with and without CHX contact. PCS was the material most affected by CHX in terms of physical properties, whereas for AH Plus, solubility was increased. CHX did not affect the physical properties of BioRoot RCS, except for reduced solubility. CHX contact did not change sealers’ alkalinity in distilled water whereas alkalinity increased for AH Plus and BioRoot RCS in saline.

– In sum, it was significant that contact to CHX improved the antibacterial efficacy of sealer leachates. However, CHX increased cytotoxicity and affected to various extent sealers’ physicochemical properties, Morisbak says.

Istockphoto by adventtr showing the root canal treatment process.

Reference:

Effect of chlorhexidine digluconate on antimicrobial activity, cell viability and physicochemical properties of three endodontic sealers.

Kapralos V, Sunde PT, Camilleri J, Morisbak E, Koutroulis A, Ørstavik D, Valen H
Dental Materials Volume 38, Issue 6, June 2022, Pages 1044-1059
https://doi.org/10.1016/j.dental.2022.04.013

NIOM Newsletter November 2022