SUITA, Japan: The World Health Organization reports that cardiovascular disease is the leading cause of death globally, and there are proven links between cardiovascular disease and periodontal disease. A recent study by a team at Osaka University Hospital has investigated whether the timing of toothbrushing affects the risk of developing cardiovascular disease. It turns out that the importance of brushing at night expands beyond the benefits of tooth retention.
For the study, researchers enrolled 1,583 patients aged 20 years and older who were hospitalised for surgery, other medical treatment or examination. They found that participants who brushed their teeth both in the morning and at night and those who brushed only at night had significantly higher survival estimates for cardiovascular events compared with those who did not brush their teeth at all. Additionally, smokers who did not brush had a worse prognosis for cardiovascular onset events than did smokers who brushed only in the morning, only at night or both, and non-smokers who did not brush or who brushed only in the morning also showed worse prognosis on hospitalisation.
The researchers concluded that brushing teeth at night is important for reducing the risk of cardiovascular disease. They suggested that increased intra-oral bacterial load during sleep owing to reduced salivary flow may cause periodontal disease or dental caries, impairing mastication and spreading oral bacteria to the intestines and blood, thereby negatively affecting general health and leading to cardiovascular events. However, the authors recommended undertaking a multicentre study with a longer observation period to generalise the study results and explore the mechanism behind the observed relationship between toothbrushing timing and cardiovascular disease risk.
While the study’s findings are limited to hospitalised patients and cannot be generalised to healthy populations, they highlight the significance of proper toothbrushing habits for maintaining good oral and systemic health. The study emphasises the importance of increasing awareness about appropriate toothbrushing timing in the general population to potentially prevent cardiovascular disease.
The study, titled “Not brushing teeth at night may increase the risk of cardiovascular disease”, was published on 28 June 2023 in Scientific Reports.