Biochemical Mapping of the Inflamed Human Dental Pulp

Abstract

Dental pulp inflammation, caused by the evolution of caries, involves numerous interrelated activities at a cellular and molecular level. Cytokines, proteases, growth factors, and other biomarkers of the host response may take part in dental pulp’s immune defense. The aim of this pilot study was to determine the levels of inflammation, oxidative stress, and extracellular matrix degradation biomarkers in healthy and symptomatic irreversibly inflamed dental pulp samples from children and adolescents. Twenty-three dental pulp samples were collected from permanent teeth with irreversible inflammation, while nineteen healthy dental pulp samples were obtained from teeth extracted for orthodontic reasons. Pulp lysates were obtained and the levels of IL-2, IL-17, TNF-α, SOD3, TGF-β1, catalase, osteocalcin, MMP-7, and MMP-9 were determined using the enzyme-linked immunosorbent assay (ELISA) technique. We detected significantly higher levels (p < 0.001) of IL-2, IL-17, TNF-α, SOD3, osteocalcin, and TGF-β1 in pulp samples with irreversible inflammation than in controls. Catalase and MMP-7 showed higher levels in the experimental group, while MMP-9 showed slightly increased levels in the control group, but none of these differences were statistically significant (p = 0.064/p = 0.061/p = 0.625). Inflamed dental pulp samples showed an up-regulation of IL-2, IL-17, TNF-α, SOD3, osteocalcin, and TGF-β1. These biomarkers appear to have a powerful role in the inflammation process of human dental pulp.

Molecular biomarkers for objective assessment of symptomatic pulpitis: A systematic review and meta‐analysis

“…Accorsi-Mendonca et al ( 2013) using zymography showed higher MMP-9 activity in IRP compared to healthy control, which was confirmed by Sharma et al (2021), used fluorometric assay. Results for total MMP-9 however were not consistent with Gusman et al, 2002 showing significant increase in IRP and no significant change reported by Kritikou et al (2021) (Table S5). Only two of the included studies examined the expression of biomolecules in DF (Brizuela et al, 2020;Zehnder et al, 2011).…”

“…A few studies (Accorsi‐Mendonca et al, 2013; Gusman et al, 2002; Kritikou et al, 2021; Sharma et al, 2021), reported on the expression of MMP‐9 in healthy pulps and pulpitis with spontaneous pain, however, the presentation of the data and difference in the method of analysis and the form of MMP‐9 investigated, made it difficult to pool the results. In these studies, Gusman et al (2002) and Accorsi‐Mendonca et al (2013) using zymography showed higher MMP‐9 activity in IRP compared to healthy control, which was confirmed by Sharma et al (2021), used fluorometric assay.…”

“…A few studies (Accorsi-Mendonca et al, 2013;Gusman et al, 2002;Kritikou et al, 2021;Sharma et al, 2021), reported on the expression of MMP-9 in healthy pulps and pulpitis with spontaneous pain, however, the presentation of the data and difference in the method of analysis and the form of MMP-9 investigated, made it difficult to pool the results. In these studies, Gusman et al (2002) T A B L E 2 Summary estimates of sensitivity, specificity, diagnostic odd ratio (DOR), positive and negative like hood ratio (LR) for healthy pulps versus pulpitis with spontaneous pain.…”