03 September 2023

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Symptomatic irreversible pulpitis induces increased levels of NLRP3 in gingival crevicular fluid compared to saliva

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Aim

The goal of this case-control observational study was to compare the levels of the human nucleotide-binding domain, leucine-rich repeat, and pyrin domain-containing-3 (NLRP3) protein in the saliva and gingival crevicular fluid of patients with symptomatic irreversible pulpitis (SIP) and healthy controls.

Methods

The 16 patients in the control group were matched with the 16 patients in the SIP group to create a total of 32 patients. In addition to saliva, gingival crevicular fluid (n = 48) samples were collected from the involved tooth (n = 16), contralateral tooth (n = 16), and adjacent tooth (n = 16) in the SIP group.

Saliva and GCF were taken from the healthy group as a baseline. An independent t-test was used for statistical analysis. The random-intercept model was used to compare the average NLRP3 levels in the SIP tooth, adjacent tooth, and contralateral tooth taking age as a covariate, and the p-value was adjusted using Bonferroni correction.

Results

There were significantly higher levels of NLRP3 in the saliva of SIP patients (1.78 ± 1.14 ng/ml) compared to the healthy control (0.70 ± 0.70 ng/ml) and in the GCF of the involved tooth (5.72 ± 0.63 ng/ml) compared to healthy people (1.60 ± 0.42 ng/ml) (p <0.001).

In SIP patients the mean difference of NLRP3 levels between SIP and contralateral teeth was significant at 4.13 ng/ml [95% CI: 3.52 to 4.70 p<0.001] and a mean difference between adjacent teeth and contralateral teeth was significant at 3.53 ng/ml [95% CI: 2.94 to 4.12 p<0.001].

The NLRP3 in GCF and saliva had a negative association in the affected tooth but a negligible correlation in healthy controls.

Conclusion

The NLRP3 inflammasome has the potential to be employed as a molecular diagnostic biomarker for pulpal disorders.

Dax Abraham et al. "Symptomatic Irreversible Pulpitis induces increased levels of human NLRP3 in gingival crevicular fluid compared to Saliva- a case control observational study." Journal of Endodontics. 25 August 2023. DOI: https://doi.org/10.1016/j.joen.2023.08.013