Sleep Time Duration Does Not Affect Oral Inflammation and Periodontal Health Status in Night-Shift Workers: A Cross-Sectional Study

BACKGROUND: Night-shift workers experience circadian rhythm disruption, changes in sleep time duration, and effects on their eating habits. All these factors may be related to the release of inflammatory mediators and may affect oral inflammation and periodontal health status. The objective of this study was to analyze the effects of sleep time duration on oral inflammation and periodontal health status in night-shift workers and non-night-shift workers. METHODS: This study involved two groups with 27 participants each: one group of night-shift workers and one group of non-night-shift workers. Examination of depth of pocket and bleeding on probing (BOP) was conducted with a periodontal probe. Non-stimulating saliva samples were collected to analyze the levels of melatonin, malondialdehyde (MDA), and tumor necrosis factor α (TNF-α) using ELISA. Comparisons for each parameter were performed using independent t-tests, and the relationships between duration of sleep and depth of pocket, BOP, salivary melatonin, MDA, and TNF-α were calculated using linear regression. RESULTS: The night-shift worker group had a short sleep time duration (p = 0.000). The salivary melatonin level of the night-shift workers was lower than that of the non-night-shift workers (p = 0.000). MDA, depth of pocket, and BOP were higher in the night-shift workers (p = 0.000). Only salivary melatonin showed a correlation with sleep time duration in the night-shift worker group (p < 0.05). Neither subject group showed an effect of sleep time duration on depth of pocket, BOP, salivary melatonin, MDA, or TNF-α (p > 0.05). CONCLUSION: Night-shift workers showed higher rates of oral inflammation and periodontal health status, but there was no relationship between these factors and sleep time duration.