By using the 4th Chinese National Oral Health Survey, the study aimed to investigate the association between tooth retention and health behaviors among Chinese older adults. We found that participants who had more than 20 teeth were more likely to have healthy behaviors than those who had less than 20 teeth. Moreover, we found that the use of toothpicks, dental floss, toothpaste, smoking, and dental visits were significantly associated with the number of remaining teeth. The frequency of brushing was not significantly related to the number of remaining teeth in adults, which was different from the foreign study that showed that higher frequency of toothbrushing was associated with more remaining teeth [32]. This may be because respondents did not brush their teeth properly and/or the frequency of toothbrush was low [33], therefore, their oral health status is not ideal. Some Chinese scholars have found that Chinese adults' attention to oral health is behind developed countries, good oral hygiene behaviors were not formed [34]. This may explain why the frequency of toothbrushing was not associated with the number of remaining teeth in China. This suggests that when we want to enhance people’s awareness of oral health, especially for those over aged 55 or older, proper brushing techniques should be pointed out. The use of toothpicks, dental floss, and toothpaste is conducive to the retention of teeth. As toothpicks and dental floss are used to get rid of food debris between teeth, toothpaste as a cleaning agent can better help clean teeth and remove plaque and slow down the accumulation of dental calculus. Good oral hygiene can effectively keep or improve periodontal health, as periodontitis is mainly accountable for tooth loss in adults.
Older adults who never smoked were more likely to have more than 20 remaining teeth than those who were current smokers. Tobacco contains a variety of harmful substances that can directly stimulate periodontal tissues or enter the bloodstream, causing periodontal damage. Azodo's research on Nigeria residents' smoking and oral health behaviors found that smokers had poorer subjectively rated periodontal health and poorer oral selfcare behavior [35] which is similar to our study.
People who had more dental visits were less likely to have more than 20 remaining teeth. This may be because Chinese adults seek dental services for treatment rather than prevention and patients who seek dental consultations have poor oral conditions [36], which is different from what is seen in studies from developed coutries [37]. Secondly, Chinese scholars have found that 28% of Chinese older adults have no remaining teeth and that only 19% had dental care in the past year [38]. This shows that people with dental problems are not active in seeking dental care. The third reason is that the treatment is not performed at the optimal time, resulting in pain and lack of other treatment options as the main reasons for tooth extraction [39]. Murakami and other scholars reported that once oral diseases occur, due to lack of dental insurance and costly treatments, older adults are reluctance to seek timely dental treatment [40]. This finding indicates that increase access to dental care is critical for improving timely dental care and regular dental visits.At the same time advocate restoration projects for missing teeth to maintain oral function.
The average life expectancy of a Chinese resident is increasing every year. According to the data released by National Health Commission of the People’s Republic of China [41], the average life expectancy of a Chinese resident in 2018 was 77.0 years. Multidimensional improvement of the quality of life of older adults has become a research priority [11]. However, oral health is an important part of general health, and oral diseases such as missing teeth, are inextricably linked to the occurrence of other diseases [42]. Based on this, it is necessary to start with oral hygiene behaviors to improve the life of natural teeth and maintain oral function, therefore improving the overall health and quality of life of older adults. Health administrative departments should continue to promote the construction of medical associations when implementing the ‘Healthy oral action plan’ (2019–2025) [43]; formulate regional oral health development plans for older adults in different regions, especially for those from rural areas; and provide quantitative oral health funding subsidies to low-income people to improve access to health care, promote the transformations of disease treatments in health management [44]. To help residents to acknowledge better oral health behaviors and save more teeth, their communities should increase the accessibility of oral health education to instruct residents to keep or develop a healthy lifestyle.
There are several limitations in this study. First, due to the cross-sectional research design of this study, we cannot identify causal relationships between health behaviors and the number of remaining teeth. Second, there may have bias in the oral health related oral hygiene behavior due to self-reported nature of the study. partial dependent variable, because it was self-reported by the participants. However, this study also has strengths. We used a representative sample of the whole Chinese population using the 4th Chinese National Oral Health Survey. This oral health survey is the only large national study that includes clinical examinations of oral health in older adults. Also, we controlled for both the subjective and objective oral health statuses in this study.
In conclusion, the use of toothpicks, dental floss, and toothpaste were protective factors to the number of remaining teeth, whereas smoking and dental visits were risk factors to the number of remaining teeth among Chinese adults. It is important to promote proper health behaviors to prevent tooth loss. Future studies are needed to develop interventions to help people retain more teeth.