Evaluation of periodontal ligament cell viability in different storage media based on human PDL cell culture experiments—A systematic review

BACKGROUND/AIMS The best treatment for an avulsed tooth is immediate replantation. If this is not possible, a proper transport medium is required for the maintenance of viability of the periodontal ligament cells (PDL). The aim was to systematically review the efficacy of different storage media used for the survival of PDL cells of avulsed teeth in the in vitro setting. METHODS The search strategy was based on the MeSH keywords in PubMed/MEDLINE: "Transport media for avulsed teeth," "Storage media for avulsed teeth," "Knocked out teeth," "Tooth avulsion," "Biological transport of avulsed tooth," "Cell survival of avulsed tooth," "Cell viability of avulsed tooth," "Tooth replantation," and "Periodontal ligament in avulsed teeth." The "AND" and "OR" Boolean operators were applied to combine keywords. Each study was evaluated for eight criteria, including use of human PDL, in vitro cell culture models, the number of passages, types of storage media, percentages of surviving PDL cells, pH and osmolality of storage media, and the type of test used to asses PDL viability. RESULTS In 15 selected studies, nine storage media (HBSS, tap water, DMEM, milk, saliva, 10% and 20% propolis, Gatorade, and Viaspan) were analyzed at six time points. For storage up to 2 hours, HBSS, DMEM, milk, 10% propolis, 20% propolis, and Viaspan conserved more than 80% of PDL viability. For storage at 24 hours, Viaspan showed best cell survival at 88.4%, followed by DMEM (70.9%) and 10% propolis (68.3%). Milk and HBSS showed similar PDL survival at 24 hours (57.2% and 57.3%, respectively). CONCLUSIONS Milk remains the most convenient, cheapest, and readily available solution in most situations while also being capable of keeping PDL cells alive. Further studies are required to evaluate the efficacy of more commonly found storage media besides milk.