Imagine that you could engineer tissue to restore root canals to their healthy state so the root and surrounding tissue could continue to develop. Regenerative endodontics uses biologically based procedures to replace damaged tooth structures. Instead of filling the pulp chamber with biologically inert material during root canals, it inserts bioactive substances or stimulates the existing cells to regrow native tissue.
Some research suggests that apical papilla cells (APCs) can play a role in tissue regeneration and root continuation. Preserving cell vitality and promoting initial cell attachment, then, would be key to a successful procedure.
One recent study investigated the attachment ability and morphology of viable human APCs by using fibronectin immunofluorescence, AbD Serotec’s alamarBlue assay, and scanning electron microscopy (SEM) when APCs were grown on human root dentin surfaces treated with 3Mix or calcium hydroxide [Ca(OH)2] at different concentrations.
The researchers divided human root dentin slices into 6 groups: control; 3Mix 0.39 mg/mL; 3Mix 100 mg/mL; 3Mix paste; Ca(OH)2 1.0 mg/mL; and Ca(OH)2 1,000 mg/mL. Next, the researchers separately treated all of the samples for 7 days and final-rinsed them with 17% ethylenediaminetetraacetic acid (ETDA). Primary human APCs were seeded as well.
To evaluate the attachment ability of APCs on treated dentin, the researchers used fibronectin immunofluorescence. They also monitored a vitality assay by using alamareBlue at specific time intervals and observed the morphology of the cells on the dentin under SEM.
The researchers observed the lowest number of fibronectin-positive cells on root dentin treated with 3Mix paste (P < 0.05). The 3Mix at 0.39 and 100 mg/mL did not affect the amount of APC attachment. The viability of APCs on the dentin surface also was significantly lower in the 100-μg/mL 3Mix-treated group than in the negative control group (P < 0.05).
Meanwhile, both concentrations of Ca(OH)2 induced APC attachment (P < 0.05). Also, only cells grown on the surfaces treated with Ca(OH)2 exhibited cytoplasmic processes.
The study, “Attachment Ability of Human Apical Papilla Cells to Root Dentin Surfaces Treated with Either 3Mix or Calcium Hydroxide,” was published by the Journal of Endodontics. It was written by Pattama Kitikuson, DDS, and Tanida Srisuwan, DDS, Dip Clin Dent, PhD, of the department of restorative dentistry and periodontology, faculty of dentistry, at Chiang Mai University in Thailand.