MMP-9 in Dentinal Fluid Correlates with Caries Lesion Depth

Area of Science:

• Dental Research
• Biomarkers
• Caries Diagnostics

Background:

• Molecular analysis of dentinal fluid offers potential for improved caries diagnostics.
• Matrix metalloproteinases (MMPs) are implicated in tissue breakdown and turnover.
• Matrix metalloproteinase-9 (MMP-9) is linked to neutrophil-mediated pulp tissue damage.

Purpose of the Study:

• To investigate if dentinal fluid levels of MMP-9 increase with the progression of carious lesions.
• To compare MMP-9 levels in deep versus shallow carious lesions.
• To contrast MMP-9 levels with MMP-2, an indicator of normal tissue turnover.

Main Methods:

• Dentinal fluid was collected from deep and shallow caries in molars and premolars of 30 adult patients.
• Enzyme-linked immunosorbent assay (ELISA) was used to quantify MMP-9 and MMP-2 levels.
• Nonparametric statistical tests (Wilcoxon, Spearman) were applied for data analysis.

Main Results:

• Significantly higher MMP-9 levels were found in dentinal fluid from deep carious lesions compared to shallow ones (p < 0.05).
• Pairwise comparisons within patients showed more MMP-9 in deep lesions for 27 out of 30 individuals (p < 0.001).
• No significant difference in MMP-2 levels was observed between deep and shallow lesions; MMP-9 levels were highly correlated between lesion depths (ρ = 0.72, p < 0.001).

Conclusions:

• Elevated MMP-9 in dentinal fluid correlates with the progression of dental caries.
• MMP-9 shows potential as a diagnostic biomarker for assessing caries severity in minimally invasive treatment.
• MMP-9 levels reflect lesion depth, while MMP-2 does not, suggesting specific roles in caries pathology.