Determination of Periodontal Ligament Cell Viability in Long Shelf-Life Milk

The purpose of this study was to determine the ability of long shelf-life milk to serve as a temporary storage medium for the maintenance of periodontal ligament (PDL) cell viability on avulsed teeth. PDL cells were plated onto 24-well culture plates and allowed to attach for 24 h. Minimal Essential Medium was replaced with regular pasteurized milk (refrigerated milk), long shelf-life milk (Parmalat®), or Save-A-Tooth™. Tap water served as the negative control, and Minimal Essential Medium served as the positive control. The tissue culture plates were incubated at 37°C for 1, 2, 4, or 8 h. Cell viability was determined using a cell proliferation assay (CellTiter 96™ AQ Assay) and absorbance read at 490 nm. ANOVA indicated that all media performed significantly better than tap water at all time periods. At 8 h, PDL cell viability in regular pasteurized milk and long shelf-life milk were significantly greater than in Save-A-Tooth™ (p ≤ 0.001). There was no significant difference between regular pasteurized milk and long shelf-life milk at any time period. These results suggest that long shelf-life milk, which has the advantage of not requiring refrigeration, is as effective a storage medium for avulsed teeth as regular pasteurized milk and more effective than Save-A-Tooth™.