Comparison of different graft materials on the proliferation, mineralization and mineralized tissue-related gene expressions of cementoblasts

Cementoblasts and formation of new cementum are crucial for periodontal regeneration. The aim of this study is to investigate the effect of different graft materials on cementoblast's proliferation, mineralization and mineralized tissue-related gene expressions in-vitro. Immortalized mouse cementoblasts (OCCM-30) were treated with the media containing released components of graft materials (100 mg/ml ratio; waited in 5% FBS containing media for 3 days). Proliferation of the cells was evaluated using a real-time cell analyzer for 170 h and wound healing assay was performed to determine the migration of OCCM-30 cells. Total RNA was isolated on days 3 and 6, and biomineralization of the cementoblasts was assessed using von Kossa staining. mRNA expressions of bone sialoprotein (BSP), osteocalcin (OCN), collagen type I (COL-I), runt-related transcription factor2 (Runx2), and alkaline phosphatase (ALP) genes were examined using quantitative RT-PCR. While there was no significant difference at 72 h, all test groups showed significant reduction of cementoblast's proliferation at 96^th and 120^th h. All graft materials increased cell migration to the experimental wounded area. While Bio-Oss^® showed significantly better effects on all mineralized tissue associated gene mRNA expressions on day 3 (p < 0.01), Nanobone^® upregulated Runx2 (p < 0.01) and BSP (p < 0.05), Emdogain^® induced OCN (p < 0.05) and Runx2 (p < 0.05). Endobon^® upregulated Runx2 only on day 3 and 6 (p < 0.05). The most prominent increase in mineralized nodule formation was observed in Nanobone^® (p < 0.05). In conclusion, released components of all graft materials have positive effects on the cementoblast's functions while Bio-Oss^® might be preferable for gene expressions. Nanobone^® has superiority for the biomineralization of the cementoblasts. The interaction of the graft materials and the cementoblasts is critical for the formation of new cementum required for periodontal regeneration.