Attachment and growth of dental pulp stem cells on dentin in presence of extra calcium.

OBJECTIVE:We aimed to differentiate dental pulp stem cells (DPSC) to odontoblast-like cells (ODPSC) and to investigate their attachment and growth on dentin in the presence of extra calcium by colorimetric assay and scanning electron microscopy (SEM). METHODS:After isolation of DPSC, they were differentiated to ODPSC. Standard dentin discs from human molar teeth were prepared. While the dentin discs in Group 1 did not receive any extra treatment, the discs in Group 2 were treated with acidic calcium phosphate precipitation (CPP) solution. In Group 3, the discs were suspended in phosphate buffered saline containing calcium. DPSC or ODPSC (3×10(4) cells/mL) were seeded on all discs and incubated for 7, 14 or 21 days. Attachment and growth of 7-day cell cultures on extra dentin samples were examined by SEM. MTT assay showed that number of cells on dentin surfaces was increased by time periods regardless of type of treatment and cells (p<0.05). RESULTS:While DPSC and ODPSC showed similar proliferation rates at 7 and 14days (p>0.05), the number of ODPSC was higher than DPSC in 21-day samples (p=0.039). MTT assay showed that number of cells on dentin surfaces was increased by time periods regardless of type of treatment and cells (p<0.05). Calcium-treated dentin surfaces always had lower number of cells; being significant for only CPP-treated surfaces (p<0.01). Both types of cells demonstrated good attachment and proliferation on dentin surfaces regardless of type of dentin treatment. CONCLUSIONS:Because the nature of dentin surface itself showed good adhesive characteristics with ODPSC and DPSC, additional calcium treatment of dentin surfaces may not be necessary.