Assessment of salivary tumor necrosis factor‑alpha level in the initial stages of treatment with fixed appliances and clear aligners

OBJECTIVES: To assess and compare the tumor necrosis factor‑alpha (TNF‑α) levels in saliva samples during the initial stages of orthodontic treatment with fixed orthodontic appliances (FAs) and clear aligners (CAs). MATERIALS AND METHODS: This longitudinal study comprised 40 patients (22 males, 18 females, mean age 22 ± 7 years) who were categorized into two equal‑sized groups. Group A comprised 20 patients treated with FA, and Group B comprised 20 patients treated with CA. Unstimulated saliva was collected before the intiation of treatment and then collected again after the placement of the FA/CA at 24 hrs, 7^th day, and on the 21^st day in both groups. TNF‑α levels were determined through ELISA. STATISTICAL ANALYSIS: The data were subjected to statistical analysis. For intragroup comparison of TNF‑α at different time points, the Wilcoxon matched‑pairs signed‑rank test was used, and for intergroup comparison of FAs and CAs at different time points, the Mann–Whitney U test was used. RESULTS: TNF‑α levels in the saliva increased significantly at 24 hours, followed by a decline on the 7^th day and 21^st day in both groups. Changes in TNF‑α levels were significantly higher in the FA group than those in the CA group at different time points. CONCLUSION: This study showed that the salivary TNF‑α levels increased significantly during the initial stages of FA and CA treatment at different time points. The mean salivary TNF‑α level in both FA and CA groups increased significantly at 24 hours, followed by a decline on the 7^th day and then on the 21^st day. There was a significant difference between the FA and CA treatment, where the CAs showed a significantly low level of TNF‑α in saliva at different intervals of time when compared to the FAs.