Effect of storage media on pulp cell proliferation capacity of open apex teeth in rabbits

The proliferative capacity of dental pulp cells after replantation in the alveolus facilitates pulp regeneration and subsequent root maturation. The aim of this study was to compare milk, egg white and HBSS (Hanks Balanced Salt Solution) to maintain pulp cell's proliferative capacity in open apex teeth in rabbits. Sixty open apex incisors of rabbits were randomly stored for one, three and six hours in tubes containing milk, egg white and HBSS at 4°C, immediately after open surgical extraction. Following fixation and decalcification of the teeth, three histologic sections were prepared from the coronal, middle and apical thirds of the pulp and the presence of Ki-67 antigens was evaluated in the sections by immunohistochemical methods. The mean values of liability index were analyzed using repeated measures ANOVA (α=0.05). Liability index of dental pulp cells stored in milk at one-hour, three-hour, and six-hour intervals were 13.7±4.37, 14.56±4.11, and 15.52±6.56; these indexes in egg white were 14.90±2.87, 17.66±5.9, and 12.23±3.87 and for HBSS they were 14.60±1.57, 14.14±5.02, and 18.85±6.54, respectively, during the same intervals. Pulp cells stored in milk, egg white and HBSS exhibited the same proliferative capacity at one-hour, three-hour, and six-hour intervals, with higher proliferative capacity in the apical third compared to the middle and in the middle third compared to the coronal third.