A Biomimetic Approach for Treating Deep Dentin Carious Lesions Using Dentin Matrix Protein (DMP-1): An In Vitro Comparative Study.

OBJECTIVES

To evaluate the potential of a phosphoprotein analogue to mediate mineral deposition and enhance surface integrity in deep carious dentin lesions, compared with mineral trioxide aggregate (MTA) and Sylc air abrasion.

MATERIALS AND

METHODS

Thirty carious dentin discs (3.5 ± 0.1 mm in thickness) were prepared and examined visually (ranging from yellow to light brown), through tactile assessment (leathery sensation), with 0-20 DIAGNOdent pen readings indicating caries-affected dentin (CAD) substrate. The specimens received three treatments: dentin matrix protein-1 (DMP-1, MCE, United States), MTA (Angelus, Brazil), and Sylc air abrasion (AquaCare, United Kingdom), and were immersed in artificial saliva (pH 7, 37°C) for 30 days. Fourier-transform infrared spectroscopy (FTIR) and contact angle measurement were performed on DMP-1. The mineral and organic content was assessed using Raman micro-spectroscopy, while cross-sectional tissue hardness was evaluated by a Vickers tester at 50 and 100 µm depth from the treated surfaces. The morphological assessment was conducted using scanning electron microscopy (SEM).

STATISTICAL ANALYSIS: One-way ANOVA followed by Tukey's multiple comparison test and paired t-test were performed for the statistical analyses.

RESULTS

The FTIR spectra of DMP-1 displayed the amide bands associated with carbonyl and N-H stretching vibrations, in addition to the phosphate band. DMP-1 exhibited good wettability (contact angle of 27°), and enhanced the phosphate and organic content and tissue hardness of the treated CAD surfaces compared with pretreatment values (p < 0.05). Meanwhile, the MTA-treated surface demonstrated the highest phosphate content and Vickers hardness number up to 100 µm (p = 0.005). The SEM showed compact surfaces completely covered with mineral precipitation.

CONCLUSION

DMP-1 provided a successful biomimetic analogue that enhanced the mineral-organic phases of mineral-depleted dentin surfaces, offering an effective treatment modality for deep carious lesions compared with MTA and Sylc air abrasion.