PMID- 34081782
OWN - NLM
STAT- MEDLINE
DCOM- 20210913
LR  - 20220621
IS  - 1365-2591 (Electronic)
IS  - 0143-2885 (Linking)
VI  - 54
IP  - 10
DP  - 2021 Oct
TI  - Assessment of the cytotoxic effects and chemical composition of the insoluble 
      precipitate formed from sodium hypochlorite and chlorhexidine gluconate.
PG  - 1892-1901
LID - 10.1111/iej.13583 [doi]
AB  - AIM: To investigate (1) the cytotoxic potential of the brown precipitate (BP) 
      formed with sodium hypochlorite (NaOCl) and chlorhexidine gluconate (CHX), using 
      both a small animal model of Caenorhabditis elegans (C. elegans) and cultured 
      human gingival fibroblasts; and (2) the chemical composition of BP using 
      Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). METHODOLOGY: Brown 
      precipitate was obtained by mixing equal volumes of 6% NaOCl and 2% CHX and 
      separating the BP from clear supernatant by centrifugation. The brown precipitate 
      was weighed and solubilized in dimethyl sulfoxide for cytotoxicity experiments. 
      The cytotoxic effect of BP was assessed using C. elegans larvae and primary 
      immortalized human gingival fibroblasts-hTERT (hTERT-hNOF) cells. Various 
      dilutions of BP (25 ng/microL-150 ng/microL), supernatant (0.15% v/v), NaOCl 
      (1:100-1:1000 dilutions of 6% NaOCl) or CHX (1:500-1:1000 dilutions of 2% CHX) 
      along with vehicle control (0.5% v/v ethanol and 0.15% v/v DMSO) or untreated 
      control (growth medium) were tested on C. elegans larvae and hTERT-hNOF cells. 
      Viability was assessed in C. elegans larvae using stereomicroscopy and in 
      hTERT-hNOF cells using dehydrogenase-based colorimetric assay. ToF-SIMS was used 
      to assess the chemical composition of BP in comparison with CHX and 
      para-chloroaniline (PCA). The C. elegans and cell line data were analysed using 
      Log-Rank test and Student's t-test, respectively (p < .05). RESULTS: BP-75 ng/microL 
      and BP-150 ng/microL were significantly more toxic to C. elegans larvae than the 
      untreated, vehicle, supernatant or CHX treatment groups (p < .0001). Similarly, 
      in hTERT-hNOF cells, BP-50 ng/microL, BP-75 ng/microL and BP-150 ng/microL induced 
      significant cytotoxicity within 2 h compared with untreated, vehicle, supernatant 
      and CHX treatments (p < .05). ToF-SIMS analysis of BP revealed ion composition 
      characteristic of both CHX and the carcinogen PCA. CONCLUSIONS: Brown precipitate 
      was toxic in both C. elegans larvae and hTERT-hNOF cells. The ToF-SIMS analysis 
      of BP revealed ions characteristic of CHX and PCA that could account for the 
      toxicities observed in C. elegans larvae and human gingival fibroblasts. Because 
      of the insoluble and toxic nature of BP, consecutive use of CHX and NaOCl 
      irrigants should be avoided in root canal treatment.
CI  - (c) 2021 British Endodontic Society. Published by John Wiley & Sons Ltd.
FAU - Jeong, Ji Wook
AU  - Jeong JW
AD  - Department of Endodontics, School of Dentistry, The University of Texas Health 
      Science Center at Houston, Houston, TX, USA.
FAU - Sarmast, Nima D
AU  - Sarmast ND
AD  - Department of Periodontics, School of Dentistry, The University of Texas Health 
      Science Center at Houston, Houston, TX, USA.
FAU - Terlier, Tanguy
AU  - Terlier T
AD  - SIMS Laboratory, Shared Equipment Authority, Rice University, Houston, TX, USA.
FAU - van der Hoeven, Ransome
AU  - van der Hoeven R
AD  - Department of Diagnostic and Biomedical Sciences, School of Dentistry, The 
      University of Texas Health Science Center at Houston, Houston, TX, USA.
FAU - Holland, Julian N
AU  - Holland JN
AD  - Office of Research, School of Dentistry, The University of Texas Health Science 
      Center at Houston, Houston, TX, USA.
FAU - Parikh, Neha
AU  - Parikh N
AUID- ORCID: 0000-0001-7864-3020
AD  - Department of Diagnostic and Biomedical Sciences, School of Dentistry, The 
      University of Texas Health Science Center at Houston, Houston, TX, USA.
LA  - eng
GR  - American Association of Endodontists Foundation/
GR  - American Association of Dental Research-Houston Section/
GR  - CBET-1626418/National Science Foundation/
PT  - Journal Article
DEP - 20210701
PL  - England
TA  - Int Endod J
JT  - International endodontic journal
JID - 8004996
RN  - 0 (Root Canal Irrigants)
RN  - DY38VHM5OD (Sodium Hypochlorite)
RN  - MOR84MUD8E (chlorhexidine gluconate)
RN  - R4KO0DY52L (Chlorhexidine)
CIN - Int Endod J. 2022 Jun;55(6):685-688. PMID: 35511028
CIN - Int Endod J. 2022 Jun;55(6):689-691. PMID: 35511029
MH  - Animals
MH  - Caenorhabditis elegans
MH  - Chlorhexidine/analogs & derivatives/toxicity
MH  - Humans
MH  - *Root Canal Irrigants
MH  - *Sodium Hypochlorite/toxicity
OTO - NOTNLM
OT  - brown precipitate
OT  - chlorhexidine
OT  - eukaryotic model
OT  - para-chloroaniline
OT  - sodium hypochlorite
OT  - toxicity
EDAT- 2021/06/04 06:00
MHDA- 2021/09/14 06:00
CRDT- 2021/06/03 17:21
PHST- 2021/05/28 00:00 [revised]
PHST- 2021/02/11 00:00 [received]
PHST- 2021/06/01 00:00 [accepted]
PHST- 2021/06/04 06:00 [pubmed]
PHST- 2021/09/14 06:00 [medline]
PHST- 2021/06/03 17:21 [entrez]
AID - 10.1111/iej.13583 [doi]
PST - ppublish
SO  - Int Endod J. 2021 Oct;54(10):1892-1901. doi: 10.1111/iej.13583. Epub 2021 Jul 1.