Analysis of MMP-8, MMP-20, and TGF-β1 in molar-incisor hypomineralization and assessment of periodontal health.

Background: Gingival crevicular fluid (GCF) volume can be used to evaluate periodontal diseases, along with matrix metalloproteinase-8 (MMP-8) and transforming growth factor-beta 1 (TGF-β1) found in GCF. Conversely, matrix metalloproteinase-20 (MMP-20) is implicated in amelogenesis and serves as a potential biomarker for assessing enamel mineralization. In this context, the present study aims to investigate the effect of molar incisor hypomineralization (MIH) on periodontal health and to evaluate the relationship between MIH and GCF volume, as well as GCF biomarkers such as MMP-8, MMP-20, and TGF-β1.

Methods: The study was conducted on a total of 40 pediatric patients diagnosed with MIH (Study Group/SG), and 40 pediatric patients healthy for MIH (Control Group/CG). Clinical periodontal measurements (plaque index (PI), gingival index (GI), probing pocket depth (PPD), and GCF volume were performed. Concentrations of MMP-8, MMP-20, and TGF-β1 in GCF were determined using the enzyme-linked immunosorbent assay (ELISA). Mann-Whitney U test and T-test were used for statistical comparisons between groups. Binary Logistic Regression Analysis was performed for independent risk factors affecting MIH status. Finally, the ROC curve was used to determine the optimal cut-off value for MMP-20.

Results: PI, GI, PPD, and GCF volume values were significantly higher in the SG than in CG (p < 0.001, p = 0.007, p = 0.001, p = 0.007, respectively). According to binary logistic regression analysis, a one-unit decrease in MMP-20 level increased the risk of MIH four-fold (p < 0.001). However, no significant differences between the groups in terms of MMP-8 and TGF-β1 were observed (p = 0.564, p = 0.088, respectively). Finally, a significant area under the curve (AUC) value was found in determining MIH status for the MMP-20 variable (AUC = 0.948; p < 0.001).

Conclusions: Along with the increased tendency for gingivitis in MIH, detecting low concentrations of MMP-20, one of the biomarkers known to be effective in enamel mineralization, in the GCF of patients with MIH is the first information to record in the dental literature.

Trial registration: The trial protocol was retrospectively registered under ID NCT06764043 ( https://clinicaltrials.gov/ ); Jan 7, 2025.