The purpose of this study was to ascertain the WTP for natural tooth preservation versus extraction in the Iranian population, separately for anterior and posterior teeth. The mean WTP for dental caries management varied between 1 and 94 USD depending on the treatment method. The mean WTP for treatment of a tooth with a poor prognosis was lower than the average fee charged at dental facilities, which is consistent with a lower WTP for tooth filling services when compared to the actual charges imposed on a population with limited restorative services . Additionally, this study's findings indicate that the whole WTP for dental care for a tooth with a poor prognosis is a small percentage of the GDP per capita of 2282.5 USD, as determined by the World Bank (https://data.worldbank.org/). There are studies on WTP for various health outcomes in Iran [10, 22,23,24], but studies are either too limited in the field of dentistry to compare with current research findings or too focused on the characteristics of WTP associated with dental disorders. For example, in Iran, the WTP for an orthodontic treatment cycle was 20 million Rials .
Regardless of the treatment option or whether the tooth was painful or not, the WTP for anterior tooth treatment was greater than the WTP for posterior dental treatment. Even though root canal therapy for posterior teeth is more expensive than for anterior teeth due to the greater number of canals and the higher overall treatment cost of posterior teeth, participants' WTP for anterior teeth was greater than for posterior teeth, indicating that aesthetics and appearance may be more important than mastication for some populations . Even though these claims need more research in different populations and cultures, they were not supported by data from Tanzanian patients, who were about as willing to pay (WTP) to have their back teeth filled or pulled as they were to have their front teeth filled or pulled .
The results indicated that more than 65% of participants favored tooth preservation over tooth extraction, with or without substitutes. While the frequency of such decisions varied according to the anterior or posterior tooth, it appears that patients favor more conservative treatment approaches that result in tooth lay-up [21, 26].
This research found that the WTP for treating painful teeth was higher than for treating painless teeth due to the discomfort caused. Dental decay that results in a hole or crack in their tooth and causes food retention or irritates the tongue or mucosa may result in a referral to a dentist, although the patient may refuse treatment if offered root canal therapy of a decayed painless tooth and may reply, “I'm not in pain, so it's fine.”
The study population's self-reported oral health score was low. Similarly, in all scenarios, those with zero responses had worse self-reported oral health. Around 26% of individuals had poor self-reported dental health, which should be further studied in terms of its association with an increased risk of caries. Unsatisfactory oral health behavior among diverse population groups in Iran has been demonstrated previously , but there is still a dearth of population-based studies employing standard instruments for oral health assessment . Only 15% of respondents in Tehran, Iran's capital city, reported having poor oral health when asked to characterize their current oral health . This discrepancy could be explained in part by the fact that our research population was diverse and came from all around Iran, whereas this study was conducted in Tehran, a huge metropolis city. Second, the discrepancy could be explained by the fact that participants in our study graded their dental health using a standard checklist vs. a single item in the Tehran survey cited above. This investigation indicated various percentages of zero responses. The most frequently occurring scenario for zero response was a painless posterior tooth (more than 22%), while the least frequently occurring scenario was a painful anterior tooth (12.5%). Additionally, refusal to pay for a hopeless tooth was more likely to occur in males, those with a lower level of education, those with a mismatch between revenues and expenses, and residents of smaller cities. In general, our findings reveal that sociodemographic parameters are the most influential elements influencing WTP decision-making. These results back up the study's conclusion that the choice of WTP is based on some factors, including the patient's income, the setting of the clinic, and their gender .
Participants with bachelor's or higher degrees compared to those with associates or lower degrees, working participants compared to jobless people, and participants whose income matched their expenditures all had a greater probability of having a WTP of at least 1 US dollar. This condition, which includes educated participants who are employed and earn an acceptable salary, results in a participant's economic position and ability to pay to increase in all scenarios. As can be shown from the marginal analysis, participants with an appropriate income level and employed participants had significantly higher WTP for at least 32 and 20 USD more than others in all situations. In all cases except WTP for a painful posterior tooth, females had a higher likelihood of WTP of at least 1 USD compared to males. It has been said that the WTP for oral health interventions changes for women, people with more education, and people with more money [9, 30, 31].
Additionally, when participants' ages increased, the value of WTP also increased. This goes against previous research [21, 31] that showed that younger people were more willing to pay for dental health interventions.
Participants who preferred in-office treatment had a higher probability of WTP of at least one dollar compared to those who preferred private or public clinics. The setting of oral service for treatment of teeth with a poor prognosis also showed a significant marginal effect, such that participants considered paying at least 41.55 USD less for treatment in public clinics than in private offices. In other locations, the therapeutic setting was also a significant factor in WTP [9, 32].
Participants of this study with worse self-reported oral health scores had less WTP for treatment of a poor prognosis tooth. This finding is contrary to intuition. For instance, in Italy, patients with regular once-or-twice-a-year dental checkups agreed to pay additional money for the choice of treatment for decayed teeth . In Finland, healthy people with no subjective need for dental care had a greater WTP for immediate treatment of a lost filling . Regression analysis, to better elucidate this paradox, showed that self-reported dental health varies with socio-demographic characteristics including gender, education, and domicile.
For the first time in Iran, this study conducted a national-level analysis of the WTP for natural tooth preservation versus extraction using a hypothetical scenario. The findings have practical consequences for both policymakers and insurance companies. Although this study was constrained by the nature of the online questionnaires employed, it did demonstrate the likely influence of a pandemic on WTP values. It is also worth noting that the context in which WTP questionnaires are constructed has an impact on the outcomes [34, 35]. In this study, we used ex-post contexts for the WTP scenarios in which individuals assume they have a clinical condition and they have to pay out of pocket, and so the ability to pay will have an impact on the WTP. As a substitute, in the ex-ante context, respondents pay for insurance, and the ability to pay does not have such a strong impact on the WTP. Because we only used one method to figure out WTP, and there are many others, more research using other methods to figure out WTP for oral health interventions may be needed to back up our findings.