Evaluation of the efficacy of different storage media and different extra oral dry times on the viability of periodontal ligament cells of the avulsed teeth (In vitro study)

Abstract

Background: Tooth avulsion, one of the most severe forms of dental trauma, is characterized by completedisplacement of the tooth from its alveolar socket. It accounts for 0.5% to 16% of traumatic injuries in the permanentdentition. Avulsion of permanent teeth occurs most often in children 7 to 9 years old, an age when the relativelyresilient alveolar bone provides only minimal resistance to extrusive forces. The best way to preserve a tooth that hasbeen avulsed is to put it back into its socket as quickly as possible. Several storage media had been suggested topreserve the viability of the periodontal ligament cells. It was suggested to place the tooth under the patient'stongue in cases in which immediate replantation was not possible. Eagle's culture medium had also been used forstoring teeth. Also it was suggested to store the avulsed tooth in milk, Hank's balanced salt solution or saline. Chickenegg white may also prove to be a suitable storage medium for the avulsed teeth.Materials and methods: Eighty freshly extracted lower first premolars of special criteria were used in this study. Theteeth were divided into control groups in which the teeth were left to dry after extraction for 0 minute, 30 minutes, 4hours and 8 hours before being treated with the enzymes and experimental groups in which the teeth were left to dryafter extraction for 30 minutes, 4 hours and 8 hours before being immersed in a different experimental storage mediaand then treated with the enzymes to isolate the fibroblast cells of the periodontal ligament.Results: Results of this study showed that zero minute dry time was the best time for the control group in maintainingviable fibroblast cells followed by 30 minutes, 4 hours and 8 hours dry times. For the experimental groups, 30 minutesdry time was the best time followed by 4 hours and 8 hours dry times. Results of this study also showed that Hank'sbalanced salt solution was the best storage media that maintain viable fibroblast cells of the periodontal ligament ofthe extracted teeth with a significant difference compared to the control group and with no significant differencecompared to the other experimental storage media. Results also showed that the albumin of the chicken egg,honey and the glycerol were also good storage media with no significant difference than the control group.Conclusion: Hank's balanced salt solution was the best storage media in maintaining viable cells viability.Thirty minutes dry time was the best time in maintaining viable periodontal ligament cells followed by 4 hours and 8hours dry time after teeth avulsion