Microscopic evaluation of the effect of different storage media on the periodontal ligament of surgically extracted human teeth.

The objective of this study was to microscopically evaluate the human periodontal ligament adhered to extracted teeth, after extra-alveolar period of 1 h using, as storage media, pasteurized milk (group I), chicken egg white (group II) and artificial saliva (group III). Forty intact premolars were selected, with indication of tooth extraction for orthodontic reasons. After the extraction of 30 teeth, they were maintained dried on a gauze at room temperature for 10 min, and then immersed in the selected storage media. After the established time, the teeth were washed with saline solution and placed in 10.0% buffered formalin. Ten teeth were extracted and immediately immersed in 10.0% neutral formalin (group IV). Thereafter, they were submitted to histological processing. After fixation and decalcification, the specimens were cut at the cervical, medium and apical thirds, inserted in paraffin and serially sectioned, with 6-mum thickness. They were stained by hematoxylin-eosin and analyzed under light microscopy. According to the results of quantitative analysis, there was no statistically significant difference in the number of cells per mm(2) between groups I, II and III. The qualitative analysis showed similar results in relation to the organization of collagen fibers and the number of cells in groups I and II, but group III displayed a higher disorganization of the collagen fibers and also a higher reduction in the number of cells. Based on these results, it was concluded that the quality of periodontal ligament was affected by the storage media, when compared with the control group. There was a statistically significant difference in the number of cells per mm(2) between the control group and groups I, II and III. There was no significant statistical difference in the number of cells per mm(2) between groups I, II and III.