Expression of Bone morphogenetic proteins (BMPs) in human dental pulp

Fractalkine's dual role in inflammation and hard tissue formation in cultured human dental pulp cells

This study aimed to explore the potential roles of fractalkine/CX3CR1, primarily expressed in vascular endothelial cells and has recently been identified in dental pulp cells at sites of pulp tissue inflammation, not only in inflammation but also in pulp hard tissue formation. To this end, cultured human dental pulp cells were grown in 10% FBS-supplemented α-MEM. Fractalkine was introduced to the culture, and COX-2 and dentin sialophosphoprotein (DSPP) expression levels were evaluated via western blotting. Real-time PCR was used to examine BMP-2 and Osterix mRNA expression. Calcified nodule formation was evaluated with Alizarin red staining. Results revealed that fractalkine increased COX-2 protein expression, calcified nodule formation, and BMP-2 and Osterix mRNA expression in a concentration- and time-dependent manner. DSPP protein expression also increased upon fractalkine addition. This effect of fractalkine on expression of DSPP protein was inhibited in the presence of the CX3CR1 inhibiter ADZ8797. In conclusion, our findings suggest a dual role for fractalkine in promoting pulp inflammation via COX-2 production and contributing to pulp hard tissue formation by stimulating the expression of hard tissue formation markers.

Histological Evidences of Autograft of Dentin/Cementum Granules into Unhealed Socket at 5 Months after Tooth Extraction for Implant Placement

The aim of this clinical case study was to observe biopsy tissues at 5 months after an autograft of a partially demineralized dentin/cementum matrix (pDDM) into a tooth-extracted socket exhibiting healing failure. A 66-year-old female presented with healing failure in the cavity for 2 months after the extraction (#36). Initial X-ray photos showed a clear remainder of lamina dura (#36), a residual root (#37), and a horizontal impaction (#38). The vital tooth (#38) was selected for pDDM. The third molar crushed by electric mill was decalcified in 1.0 L of 2.0% HNO₃ for 20 min and rinsed in cold distilled water. The pDDM granules (size: 0.5–2.0 mm) were grafted immediately into the treated socket. X-ray views just after pDDM graft showed radio-opaque granules. At 5 months after pDDM graft, the surface of regenerated bone was harmonized with the mandibular line, and bone-like radio-opacity was found in the graft region. The biopsy tissue (diameter: 3.0 mm) at 5 months after pDDM graft showed that mature bone was interconnected with the remaining pDDM. The novel histological evidence highlighted that newly formed bone was connected directly with both dentin-area and cementum-area matrix of pDDM. We concluded that pDDM contributed to the regeneration of bone in the unhealed socket, and this regeneration prepared the socket for implant placement. Autogenous pDDM could be immediately recycled as an innovative biomaterial for local bone regeneration.