This household survey aimed to determine the oral health status of adults living in Tabriz, Iran. This oral health survey revealed that about 72% of the study population had 20 or more teeth but that only 50% of those aged 51–65 y had 20 teeth or more. A similar study conducted in Iran among adults aged 35–44 y reported that almost all the participants had a substantial number of dental and periodontal problems . The same study also reported that 6.6% of the sample had missing teeth According to the WHO’s worldwide map of oral health, Iranian adults aged 35–44 y have a moderate level of dental caries . The current study revealed that 8% of the participants were edentulous (no natural teeth), 15.5% had a removable partial denture, and 10% had a full (lower or upper) denture. The prevalence of edentulism among adults aged 51–65 y was 20.7%. A similar prevalence of edentulism among males aged 71–92 y was reported in a U.K. study . However, there were some methodological differences between our studies and mentioned study in the field of gathering information and measurements where in that study physical examination of participants and brief oral health assessment were included .
In systematic review, a Chinese population aged 65 y had an average of 20 teeth . In a Swiss health survey, by using self-report questionnaire, the prevalence of edentulous individuals among those aged 15–24 y and 65–71 y was 0.3% and 26.8%, respectively . In a Turkish study the information were gathered through face to face administered questionnaire and an oral examination reported a higher rate (48%) of edentulism . Although the burden of oral disease and tooth loss seems to increase with age, a substantial number of Iranian middle-aged adults experience oral health problems . In the present study, more than one-third of middle-aged adults (i.e., aged 51–65 y) reported poor self-rated oral and gum health. These findings are similar to those found in a previous study, which reported poor self-rated oral health among Brazilian adults aged 20–59 y .
About one-third of the participants in the present study did not brush their teeth daily, whereas three-quarters of those aged 18–35 y brushed their teeth once a day or more. In a previous study on Iranian individuals aged 60–70 years, the authors reported that 20% of the participants brushed their teeth twice or more a day and that about half the participants brushed their teeth only once a day . Our study also demonstrated that older participants were less likely to brush their teeth twice or more a day. Lack of knowledge on the importance of oral hygiene and cultural-specific factors may influence oral health behaviors of older adults . As reported previously, younger adults seemed to be more familiar than older adults were with common and effective methods of preventive oral health care, possibly because of more interactions with community services, allowing them to obtain information about oral health preventive behavior .
In our study, only 23% of the participants reported using dental floss as part of routine oral hygiene. Recently, a systematic review and meta-analysis suggested that optimal oral health care for caries prevention and periodontal disease control required tooth brushing and dental flossing twice daily with fluoride toothpaste . The findings of the present study highlight the need for education on the importance of dental flossing, which is just as important as tooth brushing, as it removes dental plaque from embrasures (interdental spaces) and proximal tooth surfaces.
In this study, about 30% of the participants had visited a dentist once in the previous 6 mo, and the most common reason for the visit was oral/dental pain or discomfort, gums, or mouth. Similarly, Burgette et al. reported that 57% of their American study participants had visited the dentist within the past year . According to the results, the participants visited the dentist due to dental- or oral-related problems . . Thus, their dental health-seeking behavior was problem driven rather than preventive driven. Only 12.5% of the participants reported a routine check-up as the reason for their last visit to the dentist.
Mastication difficulty was the most common problem experienced by the participants, especially the older adults (51–65 y). It is assumed that tooth loss and the presence of dentures decreases chewing ability, dietary intake, and overall health. There is evidence that a mastication problem has a significant and negative impact on oral health-related QoL . Among 44% of those aged 18–35 y, toothache was the most common problem associated with reduced QoL. In a study conducted in several European countries, 10% of the sample, which included denture wearers, reported reduced QoL because of oral and dental problems . In another study, as the number of lost or decayed teeth increased, it was more difficult for participants to eat fruit (e.g., apples) .
In the present study, one-third of the participants consumed sweets with their meals every day and consumed tea with sugar daily. There is strong evidence for a significant association between a sugar-laden unhealthy diet and poor oral health [35, 36]. Poor oral health may have an indirect effect on general health by disrupting dietary intake. Oral health problems include edentulism, removable partial dentures that fit poorly, pain or cavities in teeth, and oral disease, all of which may compromise dietary intake by changing food choices [37, 38]. These oral health problems are particularly important among older people, as evidenced by high levels of tooth loss, dental caries, and periodontal disease .
Most studies on oral hygiene have focused on specific populations, such as children  or pregnant women [40, 41], or have been conducted in oral health care centers and used convenience samples . The present study adds to the literature by focusing on a large representative sample of the Iranian population. Nevertheless, the study has some limitations. First, it can be assumed that there is some selection bias, as not all eligible participants may have been at home during the interview visits. Second, only citizen of Tabriz were included in this study. Although the population of Tabriz is similar to that of other Iranian big cities where HCCs are present, it might be interesting for future studies to also focus on rural areas of Iran. Third, this study relied on self-reported oral health. Self-reports represent only the impressions of participants and are subject to response distortions (e.g., extreme or central tendency responses or socially desirable responses) . A more appropriate way to measure the dependent and independent variables would have been through observations or reports by independent evaluators. It might be interesting for future studies to combine self-reports with official dental records. Furthermore, including participants from different social classes would enhance the applicability of the findings to the general population.