Content analysis of fluoride-related posts on Instagram.

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Background

The Internet and social media have become many people’s primary sources of health information. Instagram is one of the most popular social media platforms, and users spend a significant amount of time daily on the platform. Therefore, analyzing oral health-related information shared online can help to identify the requirements of specific groups, assisting in the planning and execution of educational public health actions. As a result, this study was carried out to conduct a qualitative evaluation of fluoride-related content on Instagram in 2022–2023.

Methods

Using hashtags associated with fluoride, a search was conducted on the Instagram application in the Persian language. All fluoride-containing posts were saved, and data was collected thrice at two-month intervals. MAXQDA software version 2020 was used to categorize the collected data content based on type, quality, and quantity.

Results

The qualitative analysis included 1565 (9.45%) posts with fluoride-related content out of 16,475 total posts. After removing the duplicates, 400 posts remained, among which 282 posts (70.5%) and 118 posts (29.5%) were pro- and anti-fluoride, respectively. After qualitative analysis, 270 codes were examined and categorized into three main themes and eight subthemes: “fluoride sources,” “The advantages and disadvantages of fluoride,” and “Invalid beliefs about fluoride.”

Conclusion

The frequency of pro-fluoride use was higher than anti-fluoride posts. However, due to the high prevalence of posts containing false information on fluoride toxicity for health, ineffectiveness on caries prevention, and conspiracy theories, there is a need to improve the quality of information on fluoride by providing scientific and unbiased explanations by professionals online or during dental visits and supervising social media content.

Dental caries is one of the most prevalent chronic diseases in developing nations, and fluoride therapy is a widely used preventive measure for managing dental caries [1]. While fluoride offers significant benefits, excessive exposure can adversely affect dental health and overall well-being, leading to concerns among consumers about the safety of fluoride use and even doubts about the safety of fluoridated water and products [2]. Misperceptions about the harmful effects of fluoridated toothpaste have been previously reported among Iranian mothers [3]. The internet and social media play a critical role in shaping people’s oral health literacy, as they increasingly rely on these platforms to obtain information on oral health [4, 5]. Although accessing information via social media promotes autonomy and empowerment in health education and decision-making [6, 7], distinguishing between accurate content and misinformation can be challenging [8, 9].

As more individuals turn to social media for health information, the prevalence of disinformation and misinformation has grown. Therefore, it is essential to analyze the oral health-related information shared and consumed online to identify the needs of specific groups, thereby aiding in the planning and execution of public health interventions [10]. Instagram, with 1.35 billion users in 2023, has emerged as a significant source of health information on topics ranging from COVID-19 to vaccination [9, 11]. In recent years, several studies have focused on fluoride-related content on Instagram. For instance, Basch et al. [2] found that 32% of the posts supported fluoride use, while 63% opposed it. Similarly, Lotto et al. [8] assessed misleading fluoride-related content on Instagram, revealing that many posts were driven by financial motives and concerns about the toxicity of fluoridated water and products. Given the influence of online oral health content on public attitudes towards fluoride-containing caries prevention measures, careful monitoring is crucial. Anti-fluoridation content, in particular, is widespread on social media, often misleading the public about the economic and health benefits of fluoride [12].

To the best of our knowledge, no previous studies have analyzed fluoride content on Instagram in languages other than English, including Persian. As of 2024, approximately 55.59% of the Iranian population actively uses Instagram, making it more popular than other social media platforms such as YouTube (10.85%), Twitter (5.77%), and Facebook (4.41%) [13]. Instagram’s widespread popularity can be attributed to its versatile ability to share photos, texts, videos, and stories [13]. Given that support for or opposition to water fluoridation can vary across communities due to demographic and socioeconomic factors [14], evaluating digital information on oral health topics in different languages is crucial for community oral health regulators to identify areas where educational interventions are needed [15]. With increasing immigration rates—over half a million Iranian nationals resided in Europe in 2020, and approximately 37,000 Iranians lived in the United Kingdom in 2021 [16, 17]— —it is essential for health practitioners and policymakers to study health-related content in other languages. This approach helps recognize the educational needs of different racial and ethnic groups [15]. Therefore, the present qualitative study examined the quality of fluoride-related Persian Instagram posts from 2022 to 2023.

The protocol of the current qualitative study was approved by the ethics committee of Mashhad University of Medical Sciences (code: IR.MUMS.DENTISTRY.REC.1400.062).

Data collection

In this qualitative study, data regarding fluoride was collected from the Instagram social network with the following inclusion criteria:

• Posts that were retrieved using the relevant hashtags, including #fluoride,#fluoride_water,#fluoride_therapy,#fluoride_toothpaste,#do_not_use_fluoride,#fluoride_chemical_agents, #fluoridetherapy, and #fluoridetherapy_children.
• Posts containing videos, figures, and text
• Public pages
• Posts in Persian language

To enhance data reliability, searches were conducted three times, each spaced approximately two months apart: from 24 September to 1 October 2022 (6563 posts), from 1 January to 8 January 2023 (5214 posts), and from 10 March to 17 March 2023 (4698 posts).

Data for each hashtag was saved to a distinct file. One of the authors (MR.HY.) recorded the videos using the software Xrecorder on a cellphone and saved the posts. The Data collection was continued until reaching saturation level. In other words, no new themes emerged after the final posts; thus, data collection was considered adequate and had reached a saturation point [18]. Each post was imported to MAXQDA-18 software for qualitative data analysis.

Data analysis

For data analysis, a constant comparative technique based on the method of Corbin and Strauss was utilized [19]. The application of grounded theory to the relationship between events and the comparison of data continuously throughout data collection. Upon multiple readings of the post’s text, codes were ascribed to key terms and concepts. Two researchers, “M.H.” and “F.E.” conducted the coding independently. Disagreements were resolved through conversation and all authors expressed their ideas about the themes and sub-themes, the procedure termed “investigator triangulation.” The codes were labeled with the words in the posts and the concepts that the reader comprehended from the text. To establish the categorization of codes, similar codes were grouped into a single category. The conceptually interconnected groups were clustered along a central axis. Then, categories with related concepts and subjects were merged into a single theme. The conformity of the shared posts with scientific evidence was evaluated based on the opinions of two pediatric and community dentistry specialists. To meet the transferability criteria, a detailed description of the themes and subthemes, along with participant quotes, was included in the results section.

Trustworthiness

Lincoln and Guba’s criteria, including transferability, dependability, confirmability, and credibility, were followed to ensure the study’s validity [20].

In the present study, a total of 16,475 posts were recorded, of which 1,565 (9.45%) contained fluoride-related content. Table 1 provides a breakdown of the number of posts retrieved using each hashtag. After removing duplicate posts, the content of 400 fluoride-related posts was thoroughly evaluated. Among them, 282 posts (70.5%) advocated the use of fluoride, and 118 posts (29.5%) were against the use of fluoride. The number text, image and video posts were 178 (44.5%), 145 (36.25%), and 77 posts (19.25%), respectively. Through content analysis, 270 initial codes were identified and subsequently categorized into three main themes and eight subthemes:

Fluoride sources

Pharmaceutical sources

The sources of fluoride were classified as either pharmaceutical or natural. The former included systemic fluoride intake through drinking water, supplementation in the form of tablets or drops, fluoride gums, fluoride-enriched salt or milk, and topical fluoride.

In one post, the fluoride concentration in water was stated to be 0.7 ppm, with 50–60% effectiveness in reducing the dental caries rate. In areas with insufficient fluoride levels in the water, dentists may prescribe fluoride supplements, according to 27 posts. Fifty-two posts emphasized that fluoride supplements should be prescribed solely by dentists and based on patients’ needs.

As topical fluoride products, gels, varnish, mouthwash, toothpaste, and silver diamine fluoride were introduced (SDF). Some posts described the indications for fluoride therapy, including patients with dental hypersensitivity, those undergoing orthodontic treatment, deciduous teeth, and those at high risk for dental caries.

One hundred and twenty-three highlighted the advantages of office fluoride therapy, such as “the first step in introducing the child to dental treatments” and “fluoride therapy is a painless procedure, the products taste good, and they do not irritate children.”

There was disagreement regarding the appropriate age for using fluoride mouthwash and toothpaste. Minimum ages of 1, 2, 3, and 6 years were suggested for the use of fluoride toothpaste, with the ability to spit out the toothpaste being the most crucial criterion. The recommended minimum age for fluoride mouthwash was between 4 and 6 years old.

Fifteen posts described the fluoride mouthwash program in Iranian schools and highlighted the disadvantages of such programs, including the lack of supervision in schools and the possibility of swallowing the mouthwash.

Natural sources

As natural sources of fluoride, black tea, boiled potatoes, raisins, cucumbers, grape juice, tomatoes, and spinach were introduced. After stating that fluoride is toxic to the human body, one post introduced the natural source and stated, “A balanced amount of each mineral is necessary for the body.”

The advantages and disadvantages of fluoride

The advantages

Fluoride prevents dental caries by increasing remineralization, strength, and resistance to organic acids produced by the cariogenic, acting as an antibiotic, decreasing acid production, and preventing gingival infection, according to 83 posts.

Fluoride therapy was recommended for children every 3 to 6 months due to their limited ability to brush their teeth, and there were numerous posts about children receiving fluoride therapy in pediatric dentists’ offices.

To strengthen enamel, it was also recommended for young patients after orthodontic treatment and bracket removal. As stated in one post, “fluoride therapy is possible for adults, but more effective for patients younger than 20.”

The detrimental effect of fluoride overconsumption

The most common complication of fluoride overconsumption at a young age reported in Instagram posts was dental fluorosis. Dental fluorosis is identified as brown or white spots on teeth, and cosmetic treatments for it have been discussed in several posts. High water fluoride concentration, self-administration of fluoride products in the form of tablets, food supplements, and gummy candies, and swallowing toothpaste were the causes of excessive fluoride consumption. In numerous posts, it was stated, however, that fluorosis does not weaken the tooth structure and aesthetic defects can be treated with cosmetic restorations.

In 21 posts, overconsumption of fluoride, particularly via systemic routes, was reported to cause toxicity. Eighteen posts mentioned fluoride toxicity symptoms such as nausea, vomiting, and abdominal pain. Dairy products were recommended to reduce the effects of acute fluoride poisoning. Five posts also mentioned skin allergy as a rare side effect of fluoride therapy.

Invalid beliefs about fluoride

Conspiracy theories regarding fluoride

Mind control conspiracy theories were the most prevalent example of false information on Instagram. Several posts claimed that fluoride was used by Nazis to control the enslaved soldiers and narrow their minds. According to these posts, fluoride, vaccines, and chemtrails poison people, reduce their awareness, make them obedient, and increase their reliance on pharmaceutical companies. It was stated in one post: “Please understand, fluoride is added to your water and food to make you stupid. Fluoridated human beings can be slaves, can be ruled, can be abused, and even lose their independent intelligence.” Thirty-one of the posts called fluoride “the silent killer”, “the governmental poison,” and “fluoride is a friend who wants to harm you.”

Twenty-two posts reported the toxicity of fluoride in the human body with statements such as “using fluoride is even more dangerous than using uranium,” “fluoride is found in cockroach poison,” “fluoride is an industrial byproduct that causes fluorosis, dental loss, and death in cows,” and “fluoride was used 150–200 years ago to kill mice.”

In addition, they claimed that excessive fluoride precipitates in the pineal gland, which causes the sixth chakra to close and “disrupts our decision-making and thought process.” As a result, they recommended Terminalia chebula to eliminate it from the body. The proposed methods for removing fluoride from drinking water included exposing the water to sunlight, using alumina or active carbon filters, brewing tea in steel utensils, pouring water into clay pots, adding basil, and using an electric mixer for 5–7 min.

Detrimental effects on health

According to fifteen posts, fluoride has devastating effects on the brain, kidney, immune system, liver, heart, thyroid gland, and bone, causes cancer, lowers body pain, and reduces life expectancy and fertility. As stated in one post, “fluoride absorbed from gingiva deposits in the kidney, and when the immune system is unable to eliminate fluoride from the body, it accumulates and causes terrible health issues.”

According to 42 posts, ingesting fluoride makes children “slow-minded and weak,” reduces their attention, lowers their IQ, and causes behavioral disorders. Forty-two posts referred to fluoride as a neurotoxin, with one stating, “Sodium fluoride, like a Trojan horse, transports aluminum to the brain, causing IQ decline and Alzheimer’s. Additionally, it calcifies the pineal gland, which is responsible for the production of melatonin, causes sleep deprivation and thyroid dysfunction, and impairs thyroid function.”

Ninety-one of the posts discussed the toxicity of fluoride or the conspiracies surrounding it, followed by advertisements for commercial or homemade herbal toothpaste, “mouthwash powder” or “organic salt toothpaste” devoid of fluoride and “chemical materials.”

In addition to the caries-preventive effects of non-fluoride toothpaste, other therapeutic effects, such as anti-hypersensitivity, treatment for aphthous stomatitis, dental bleaching, elimination of halitosis, alleviation of dental pain, “preventing Herpes virus activation,” and treatment of “gum disease,” have been attributed to these kinds of toothpaste.

Adverse effects on teeth

Numerous posts described the negative effects of fluoride on tooth structure, with nineteen claiming that “fluoride damages the enamel surface” or “fluoride destroys the tooth’s outer protective layer.” They stated that fluoride causes hypothyroidism and reduces bone and tooth mineral absorption. These posts also stated that “water fluoridation does not reduce the caries rate in communities” because, despite increased fluoride use in recent years, dental decay has increased in many communities, and “people who brush their teeth three times a day have decayed teeth” or “throw out your fluoride toothpaste and see the results in 4–5 months.” In addition, they stated, “Our ancestors had perfect teeth and kept them until death; however, high caries risk has led to the loss of teeth at a young age, which has been caused by fluoride use.”

Fluoride’s positive effects exaggeration

Ten posts overstated the benefits of fluoride and claimed that fluoride therapy could replace tooth restoration and root canal treatment. In one post, for instance, it was stated that “you don’t need to visit your dentist for root canal therapy; just use fluoride mouthwash multiple times per day, and your pain will disappear.”

This study analyzed the content of contaminant-related Instagram posts published between 2022 and 2023. To the best of our knowledge, this is the first report on fluoride content on social media in Persian. Given Instagram’s widespread popularity and its effective dissemination of multimedia content, it was selected as the platform for this investigation. The findings revealed that pro-fluoride posts outnumbered anti-fluoride posts by a ratio of 2.38:1.

Most posts discussed the benefits of fluoride and its sources. Among the Instagram posts analyzed, the caries-preventive benefits of fluoride were linked to various mechanisms, including the hardening of tooth enamel and fluoride’s impact on oral microorganisms, which aligns with our current understanding of caries prevention [1]. Additionally, six posts highlighted fluoride’s role in alleviating tooth hypersensitivity, consistent with existing evidence [21].

Fluoride poisoning from the ingestion of fluoride-containing products was mentioned in 25 posts, while another 25 posts discussed tooth discoloration due to fluorosis. The literature identifies risk factors for fluorosis, including the ingestion of fluoridated products such as toothpaste and fluoride tablets, as well as the excessive consumption of fluoridated drinking water [22].

In this study, some posts claimed that fluoride had no effect on reducing dental caries. These claims were often accompanied by advertisements for fluoride-free toothpaste, conspiracy theories about fluoride, and descriptions of its negative health effects. Furthermore, 24 posts propagated false beliefs about fluoride, particularly its alleged effect on IQ decline, despite the fact that the neurotoxicity of fluoride is proven to be dose-dependent [23]. These findings suggest that Instagram users may be significantly influenced by misconceptions regarding fluoridated water and fluoride-containing oral health products. However, it is important to note that water fluoridation remains a highly safe, beneficial, cost-effective, and nondiscriminatory method for preventing caries across all age groups [24]. Several studies have analyzed content related to fluoride on various social media platforms. Mertz et al. [12] examined data from Facebook, Twitter, and YouTube during 2011–2012, reporting that anti-water fluoridation information predominated on these platforms. Conversely, Helmi et al. [25] found a more balanced representation of anti- and pro-fluoridation perspectives on Instagram in 2016.

The prevalence of false information regarding fluoride remains alarming. However, in the current study, the most frequently encountered posts were those highlighting the benefits of fluoride. This contrasts with previous studies where negative perspectives on fluoride have been more predominant. For instance, Basch et al. [2] analyzed over 300 Instagram posts containing the hashtag #fluoride at three different intervals. Their study found that the most frequently discussed topics were fluoride conspiracy theories (37.3%) and the health risks associated with fluoride (30.0%). Overall, 32% of the comments supported the use of fluoride, while 63% were opposed. Similarly, Eliacik [26] found that on Twitter, negative posts about topical fluoride treatment (26.4%) outnumbered positive ones (18.1%). On Twitter, Oh et al. [27] discovered that the words “poison” and “waste” were the most commonly used negative descriptors for water fluoridation, with negative content comprising approximately 59% of all mentions, compared to less than 15% positive content. They also noted that Twitter users were more interested in tweets emphasizing the negative health effects of water fluoridation rather than its effectiveness. On the other hand, Lotto et al. [28] reported that the popularity of “fluoride-free” tweets was partly due to public concerns about maintaining a healthy lifestyle and a preference for natural and organic products. The authors also suggested that the promotion of dental products might have fueled the trend toward fluoride-free options. Similarly, Basch et al. [29] found that widely viewed fluoride-related content on YouTube exhibited an anti-fluoride bias, focusing more on the risks than the benefits of fluoride. The higher frequency of pro-fluoride content in the present study compared to previous ones may be attributed to the timing of the study and language differences. However, a key factor in this study was the use of multiple hashtags. While most incorrect beliefs about fluoride were uncovered by searching the #fluoride hashtag, the majority of posts highlighting fluoride’s benefits were discovered through specialized hashtags such as #fluoridetherapy.

Additionally, public pages of dental professionals were included in the analysis, revealing that many educational posts were provided by pediatric dentists. These professionals actively worked to counter false information, educate the public about fluoride and its therapies, and explain the procedures involved. Therefore, professional activity on social media platforms may play a crucial role in combating misconceptions and reinforcing the effectiveness and safety of fluoride.

In a 2020 study by Lotto et al. [8] on false or misleading fluoride content on Instagram, a high prevalence of posts with fluoride-related misinformation driven by social, psychological, and financial motivations was reported. The authors noted that the majority of these posts were financially motivated, often promoting and advertising fluoride-free products and dentifrices containing natural ingredients. Consistent with our findings, they suggested that antifluoridation statements were influenced not only by ideological concerns but also by financial interests.

The widespread availability of health-related information has numerous positive effects, including enhancing patient autonomy and education [6, 7]. However, it also brings serious negative consequences, such as the ease with which anyone with Internet access can disseminate potentially incorrect, biased, misleading, or even dangerous health information [30]. Specifically, regarding our research, inaccurate information about water fluoridation or fluoride was readily accessible on Instagram. To mitigate the spread of such misinformation, authorities must recognize the harmful impacts that false statements can have on communities and should consider establishing regulations and laws to address this issue. Moreover, social media platforms should be encouraged to develop systems that screen posts for false or deceptive content before allowing messages to be sponsored. While it may be challenging to determine the intent behind such posts, it is crucial for society to begin implementing community education programs and considering potential penalties for those who spread incorrect information, all within the framework of democratic values. This issue is particularly important in developing countries, where the risk of dental caries is high and there is a significant need for cost-effective preventive measures.

This study had some limitations, and the findings should be interpreted with caution. The qualitative nature of the research limits the generalizability of the data. Additionally, private Instagram pages were not included in the analysis. However, to minimize data loss, multiple hashtags were used at three different times, spaced two months apart, until data saturation was achieved. Given the alarming frequency of inaccurate information about fluoride, further studies should also be conducted on other social media platforms, such as Twitter and YouTube, in the Persian language. Since the content shared on these platforms varies, it is important to evaluate them separately. Moreover, it is recommended that future studies include an analysis of overall user engagement on Instagram, such as the number of likes and views, and assess the sentiment of comments to gauge positive and negative reactions to pro- and anti-fluoride posts. While this study focused on the qualitative assessment of Instagram posts, incorporating these metrics would provide a more comprehensive understanding and should be considered in future research.

Water fluoridation as a preventive dental health measure has been a controversial issue from its beginning, people should be provided with unbiased, evidence based and updated scientific information. In conclusion, although the number of posts favoring fluoride use (282) outnumbered those discouraging fluoride use (118), there is a need to improve the quality of information on fluoride by providing scientific and unbiased explanations by professionals online or during dental visits, supervising social media content and re-evaluating the community’s education measures.

The datasets used and/or analyzed during the current study available from the corresponding author on reasonable request.

The current study was extracted from a master thesis (thesis number: 3329) and authors wish to thank the research deputy of Mashhad University of Medical Sciences for providing support to do this work (grant number: 4000053).

This study was funded by the Mashhad University of Medical Sciences, Mashhad, Iran.

Authors and Affiliations

1. Department of Pediatric Dentistry, School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran

   Fatemeh Esmaeilzadeh

2. Department of Pediatric Dentistry, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran

   Taraneh Movahhed & Mohammad Reza Hasani Yaghooti

3. Dental Research Center, Mashhad University of Medical Sciences, Mashhad, Iran

   Melika Hoseinzadeh

4. Department of Community Oral Health, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran

   Saber Babazadeh

Contributions

T.M. and S.B. conceptualized the main idea and designed the study. T.M. acquired the funding. F.E., MR.HY, M.H. acquired data, conducted data analysis, and wrote the original draft. TM and SB reviewed and edited the draft. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Saber Babazadeh.

Ethics approval and consent to participate

This study was approved by the ethics committee of Mashhad University of Medical Sciences (code: IR.MUMS.DENTISTRY.REC.1400.062).

Consent for publication

Obtaining consent for publication did not apply to the current study.

Competing interests

The authors declare no competing interests.

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