IADR Abstract Archives
Effect of Increased TNF-α Plasma Level on Orthodontic Induced Inflammatory Root Resorption
Objectives: TNF-α is a cell signaling protein (cytokine) involved in systemic inflammation and is one of the cytokines that make up the acute phase reaction and is produced chiefly by activated macrophages. The objective of this study was to determine if increased TNF-α plasma level has any effect on induced inflammatory root resorption
Methods: Forty male Wistar rat weighting 200-250 g were selected and randomly divided into four groups of ten. On the day 0, blood sample were taken from all animals and orthodontic appliances were placed for two groups that consisted the Stress-Experiment and Non-Stress (Positive Control) Experiment group. No appliances were placed for two remained groups (Stress Control and Negative Control) and considered for blood samples and root histologic comparison. One of these groups was exposed to stress and the other one was under standard laboratory condition. The orthodontic appliance consisted of a NiTi closed coil spring ligated to first upper right molar and incisor, exerting a 60 gr force during twenty-one-day experimental period, after which the animals were sacrificed and blood samples were taken from all of the rats. Palatal halves of two first groups were removed for histological examination and for calculation of the amount of root resorption. Blood samples were evaluated for Corticosterone and TNF-α plasma levels by ELISA method. Kruskal Wallis nonparametric test in SPSS statistical package was used for the purpose of comparison.
Results: Statistical analysis showed that there was a significant increase in TNF-α plasma levels within twenty one days. A significant difference (p<0.01) in root resorption and tooth movement was observed between the control and stress groups.
Conclusions: An increased TNF-α in plasma following exerting stress condition is correlated to orthodontic induced inflammatory root resorption.
Methods: Forty male Wistar rat weighting 200-250 g were selected and randomly divided into four groups of ten. On the day 0, blood sample were taken from all animals and orthodontic appliances were placed for two groups that consisted the Stress-Experiment and Non-Stress (Positive Control) Experiment group. No appliances were placed for two remained groups (Stress Control and Negative Control) and considered for blood samples and root histologic comparison. One of these groups was exposed to stress and the other one was under standard laboratory condition. The orthodontic appliance consisted of a NiTi closed coil spring ligated to first upper right molar and incisor, exerting a 60 gr force during twenty-one-day experimental period, after which the animals were sacrificed and blood samples were taken from all of the rats. Palatal halves of two first groups were removed for histological examination and for calculation of the amount of root resorption. Blood samples were evaluated for Corticosterone and TNF-α plasma levels by ELISA method. Kruskal Wallis nonparametric test in SPSS statistical package was used for the purpose of comparison.
Results: Statistical analysis showed that there was a significant increase in TNF-α plasma levels within twenty one days. A significant difference (p<0.01) in root resorption and tooth movement was observed between the control and stress groups.
Conclusions: An increased TNF-α in plasma following exerting stress condition is correlated to orthodontic induced inflammatory root resorption.