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 m ilk to serve as a temporary storage medium for the maintenance of periodont al ligament (PDL) cell viability on avulsed teeth. PDL cells were plated on to 24-well culture plates and allowed to attach for 24 h. Minimal Essential Medium was replaced with regular pasteurized milk (refrigerated milk), lon g shelf-life milk (Parmalat((R))), or Save-A-Tooth(TM). Tap water served as the negative control, and Minimal Essential Medium served as the positive control. The tissue culture plates were incubated at 37 degreesC for 1, 2, 4, or 8 h. Cell viability was determined using a cell proliferation assay ( CellTiter 96(TM) AQ Assay) and absorbance read at 490 nm. ANOVA indicated t hat all media performed significantly better than tap water at all time per iods. At 8 h, PDL cell viability in regular pasteurized milk and long shelf -life milk were significantly greater than in Save-A-ToothTM (p less than o r equal to 0.001). There was no significant difference between regular past eurized milk and long shelf-life milk at any time period. These results sug gest that long shelf-life milk, which has the advantage of not requiring re frigeration, is as effective a storage medium for avulsed teeth as regular pasteurized milk and more effective than Save-A-Tooth(TM).