INTRODUCTION

Herbal medicines and medicinal plants are widely used for preventive or therapeutic reasons in many ways, including local traditional medicine, prescription by healthcare professionals, self-medication and dietary supplements. A global report by the World Health Organization (WHO) in 2019 showed that 124 Member States (64%) had laws or regulations on herbal medicines within a national policy on traditional, complementary, integrative medicine ¹ . Thus, knowledge on

traditional medicine and clinical phytotherapy have been incorporated as a complementary practice into public and private health systems to provide comprehensive health care, especially for prevention and management of lifestyle-related chronic diseases in ageing populations ² . However, natural products are not always safe, and medicinal plants and herbal medicines may negatively impact health due to misuse. There are potential adverse effects and interaction of herbal medicines with other herbal products or synthetic drugs ^{3, 4} , resulting in unintentional decreased, exacerbated or null effect of the target pharmacological therapy, with possible health risks. Another common challenge is coprescription with synthetic drugs that could induce polypharmacy ⁵ . These problems are common in adults, and particularly relevant for elderly patients, who often have comorbidities, use multiple medications, or self-medicate inappropriately ^5-7 . Additionally, in contrast to synthetic drugs with isolated bioactive chemicals, herbal medicines have a system of phytocompounds with multi-target and multi-pathway actions, which can be problematic if not recognized. Therefore, the healthcare provider must assess patients’ use of medicinal plants and herbal medicines prior to treatment in order to fully understand their clinical conditions.

In dentistry, the literature has shown an increasing interest in herbal medicine for several oral health problems ^{8, 9} , but also reported adverse effects of herbal products in the oral cavity ¹⁰ and potential interaction with blood coagulation ¹¹ and anesthesia ¹² . Nevertheless, the internationally indexed literature is limited regarding the knowledge and opinions on phytotherapy indication, safety, and effectiveness among dentists in different settings of developing countries that have great biodiversity and traditional knowledge ^13-15 , and developed countries with profitable herbal industries ^{16, 17} . In Brazil, previous studies have interviewed only a few dentists working in multi-professional teams of the public health system ^{15,18, 19} , where national programs on integrative and complementary practices in primary care have been available since the late 2000s, though not fully implemented. However, private clinicians involved in oral rehabilitation are usually the ones who treat older patients with complex oral deficiencies and chronic health problems who use multiple medications. After treatment, these patients often return to the same professional for life-long maintenance and oral health care. However, this group of dental clinicians has not yet been assessed regarding their experience with phytotherapy. We hypothesize that sociodemographic (gender, age) and professional factors (post-graduate degrees, education in phytotherapy), and personal use of herbal medicine are associated with phytotherapy prescription by dentists.

The aim of this cross-sectional survey was thus to evaluate the knowledge and perceptions of oral rehabilitation practitioners on medicinal plants and herbal medicine, as well as their experiences with phytotherapy for personal use and clinical prescription in dental practice.

MATERIALS AND METHOD

The research design is an observational, cross-sectional, survey-type, descriptive-analytic, mixed methods study. This exploratory study with dental clinicians is part of an umbrella research project on phytotherapy in dentistry. The research protocol was approved by the university’s research ethics committee, in compliance with the Declaration of Helsinki, as revised in 2000, and the Brazilian regulations for research in human beings, and registered prospectively in a national system (Plataforma Brasil, CAAE: 58861222.8.0000.0075, Parecer 5.509.538).

RESULTS

A consecutive sample of 60 eligible dentists was recruited, of whom 53 responded to the survey, yielding a response rate of 88.3%. Seven dentists declined the study invitation because they did not wish to or had no time to answer the questionnaire. Descriptive statistics of sociodemographic, professional and health characteristics of the participants (Table 1) showed that participants’ ages ranged from 22 to 70 years (mean age 38.8±13.5 years), and time from dental graduation from 1 to 42 years. Most dentists had excellent or good general health, oral health, and mental health. A total 33 dentists (62.3%) reported taking medications for one or more health problems, such as hypertension, hypercholesterolemia, back pain, diabetes, etc. Related to the participants’ knowledge, attitudes, and practices regarding phytotherapy in dentistry (Table 2), a few dentists reported formal education (courses, classes) in phytotherapy for oral health care (2) or use of herbal medicine in general (4). Most dentists (33) had informal knowledge from family, friends, neighbors, and colleagues. A total 21 dentists reported using phytotherapy for personal health issues. Out of 17 dentists who prescribed phytotherapy, 14 reported doing so occasionally, and only one prescribed herbal medicine frequently. Table 3 shows the results of exploratory inferential statistics for phytotherapy prescription by dentists as a function of the variables ‘gender’, ‘age’, ‘post-graduate degree’, ‘formal education in phytotherapy’, and ‘personal use of phytotherapy’. Bivariate Fisher’s exact tests showed significant effect for the binary variables ‘age’, ‘post-graduate degree’, and ‘personal use of phytotherapy’. In the final logistic regression model (P=0.002; Cox & Snell R²=0.312), ‘post-graduate degree completed’ and ‘personal use of phytotherapy’ were significant for the outcome ‘phytotherapy prescription’. Dentists with post-graduate degrees were 7.2 times more likely to prescribe phytotherapy than those without. In relation to ‘personal use of phytotherapy’, dentists who used herbal medicine were 6.1 times more likely to be prescribe phytotherapy than those who did not.

A total 21 dentists (39.6%) reported using herbal medicine, and 12 described the specific plant and health indication. The most frequently cited plants for personal use were chamomile, lemongrass and passionfruit. Seventeen dentists (32.1%) reported prescribing phytotherapy for their patients, and seven described some details of herbal prescription. The most frequently prescribed plants were passionfruit and mallow. Only two dentists reported adverse effects when patients used prescribed phytotherapy: one patient had a drop in blood pressure, while the other had stained teeth after treatment for bad breath and aphtha. Table 4 presents the description of herbal medicines and medicinal plants used by the participants for personal reasons and professional prescription.

Table 5 shows the themes obtained from participants’ opinions on how to improve the rational use of phytotherapy in dentistry, as well as representativa excerpts of data. Twenty participants expressed their opinions on the subject, from which three themes were derived: 1) ‘Evidence on effectiveness, benefits and risks’, representing the importance of sound evidence from scientific research and traditional practices; 2) ‘Specific education in graduate and post-graduate courses’, denoting the need for formal education on the topic during academic courses; and 3) ‘Improved communication to dental practitioners’, meaning that sustained dissemination of qualified information to professionals is a priority.

DISCUSSION

This exploratory study found that almost one third of the respondents reported prescribing herbal medicine in their clinical practice. Dentists with post-graduate degrees and personal use of phytotherapy were more likely to prescribe herbal medicine to their patients, regardless of formal education on the subject. Phytotherapy was mostly prescribed to control patients’ anxiety before their dental visit, and for painful intraoral complaints in mucosa, gingiva or tongue. In addition, sociocultural factors seemed to drive dentists’ attitudes and practices regarding phytotherapy, as most of them had informal knowledge on herbal medicine from family, friends, neighbors and colleagues. These findings are important to understand the use of phytotherapy by dental practitioners since the literature contains little information on prescription of herbal medicine as a first-line or complementary treatment in dentistry. To the best of authors’ knowledge, no previous study has conducted an in-depth assessment of clinical dentists’ knowledge, attitudes and practices in phytotherapy. Previous surveys have explored the opinions of some dentists on phytotherapy, such as the use of herbal medicine in public primary health care ^{15,18, 19} , and awareness of potential adverse drug reactions ¹³ . Other studies have evaluated dental practitioners’ knowledge and practice in complementary and alternative medicine (CAM) ^{14, 17} , but not specifically in phytotherapy. In southern India, a country with ancient tradition in herbal medicine, 30% of dentists reported practicing alternative medicine in dentistry, including phytotherapy ¹⁴ . In Germany, where naturopathy and herbal industry are strong areas, medicinal plants were the first four CAM procedures cited by clinical dentists, reaching up to 64% of recommendations ¹⁷ . Among the assessed variables, personal use of herbal medicine was the main factor associated with dental prescription of phytotherapy. A preceding study also reported the dominant influence of personal beliefs and practices on the teaching of herbal medicine by full-time faculty of health sciences, including dentistry ¹⁶ . In the present sample, almost 40% reported personal use of phytotherapy for common but specific health problems such as insomnia, anxiety, gastritis, colds and low immunity. Likewise, dentists reported prescribing herbal medicine for their patients occasionally, mainly for behavioral and symptomatic reasons. The most frequently cited medicinal plants for dental prescription were chamomile, passionfruit, mallow and lemongrass, which are widely used as traditional medicine by the general public as well ¹⁸ . Other traditional medicinal plants recommended by German dentists were Arnica montana, clove, Salvia officinalis, tea tree and Aloe vera ¹¹ .

Having a post-graduate degree was another positive factor associated with dental prescription of phytotherapy. Time from dental graduation and formal education in phytotherapy were not significant factors. One possible explanation is that dentists with advanced dental education may be more open to adopting phytotherapy, which has not been regularly taught in academic healthcare courses ^{15, 18} despite the increasing educational efforts in many countries ¹ . Few dentists had received formal education in phytotherapy during their academic courses or continuing education, or from self-leaming for general or oral health purposes. On the contrary, informal knowledge on herbal medicine and medicinal plants (from family, friends, colleagues) was the most frequent source. This can be an additional explanation for the fact that most prescribed medicinal plants for dental patients were also commonly used as traditional medicine in the community ¹⁸ .

Limited specific knowledge on herbal medicine in dentistry was evident from the findings of the present study. This may act as a barrier for the rational use of phytotherapy in clinical practice. Most dentists did not know or did not respond whether they considered herbal medicine to be better than synthetic drugs in relation to cost, ease of procurement, safety, efficacy, or speed or duration of effect. In addition, about 36% of participants did not know that there is a potential risk of using herbal medicine or medicinal plant concurrently with a synthetic drug. This figure is similar to the number of Indian dentists who were not aware of potential adverse reactions to herbal medicines ¹³ , which can be a serious medical problem ^{3, 4} and affect surgical procedures ^{11, 12} . In Brazil, dentists working in the public primary healthcare sector also reported that they were not confident in prescribing phytotherapy because they lacked specific information or training ^{15,18, 19} .

In the qualitative part of this study, the respondents offered insight into the problems, needs and solutions involved in improving the rational use of phytotherapy in dentistry. The three themes identified from dentists’ opinions reflect a triad of joint, concurrent actions needed: ‘Evidence on effectiveness, benefits and risks’, ‘Specific knowledge education in graduate and post-graduate courses’, and ‘Impro ved communication to dental practitioners’. Ideally, reliable content on phytotherapy should be learned during academic education and widely disseminated to professionals. However, there is a translational gap between the production of scientific knowledge and its effective use in clinical practice.

Firstly, most dental schools do not include phytotherapy content systematically in their syllabus. Formal education during academic courses is essential to build the professional foundations of clinical practice, but scientific findings are continuously evolving and changing clinical protocols over time. Therefore, over their careers, clinicians should update their knowledge with evidence-based information from reliable sources. However, regarding the way they seek information, most dental practitioners prefer to fill a gap in their knowledge by resorting to informal sources, mainly consulting a colleague or using a general internet search ^{22, 23} . The indexed literature has provided summarized scientific evidence on the use of herbal medicine in dentistry ^{8, 9} , but clinicians may not search for and apply this information in practice. Indeed, most dental practitioners have reported lack of time to keep updated with the latest scientific articles, and low confidence level for using evidence-based search ^{22, 23} . This situation can be more problematic for professionals who do not have access to subscription scholarly journals or are not proficient in the language of the publications.

To bridge the scientific translational gap on a large scale, the third theme ‘Improved communication to dental practitioners’ focused on dissemination of practical knowledge should be taken up by dental professional organizations, as mentioned by one participant. Oficial channels of communication can help disseminate evidence-based content to be used directly in dental practice, such as updated news and clinical practice guidelines with rigorous methodology ²⁴ . Dissemination and implementation of research is a top priority in behavioral and social oral health sciences to tackle the evidence-to-practice gap and improve oral health education, promotion and care, as well as continuous professional training ^{25, 26} . It is noteworthy that this sample consisted of dentists who were seeking professional development in clinical courses to treat adult patients with complex oral rehabilitation needs. However, many patients may not disclose the use of over-the-counter medications, herbal medicine, or dietary supplements in medical and dental visits ²⁷ , while healthcare professionals may not be aware of the importance of this subject. In fact, 94% of the respondents did not ask their patients whether they used any medicinal plant. To help practitioners improve their routine procedures in dental patient anamnesis, four specific questions on medicinal plants and herbal medicines have been suggested, based on the study findings, scientific literature, and researchers’ experience (Table 6). The aims of these questions are to enquire about patients’ use of such products, and to raise awareness on the importance of reporting it before and during dental treatment.

A limitation of this preliminary study is the small number of respondents from a single location, which does not allow the findings to be generalized to the entire population of clinical dentists. However, this sample consisted of real-world dental practitioners and should be more homogeneous than samples obtained in online surveys. Moreover, as far as we know, this was the first study that collected quantitative and qualitative research data on dentists’ knowledge, attitudes and practices regarding phytotherapy. This comprehensive information was analyzed by the research team, which consisted of three members specializing in complementary and integrative medicine (clinical phytotherapy and acupuncture), and two experts in health social sciences.

The outcomes of this exploratory study will contribute to refine the research model and instrument for large-scale application among dental practitioners and clinical staff. A further step is to design a participatory research project to allow front-line dental clinicians engage with scientific knowledge production and use in practice. In addition, it would be useful to conduct a prospective

CONCLUSION

In summary, the results suggest that dentists with post-graduate degrees and who use herbal medicine for their own health issues also prescribe phytotherapy for dental patients. Most dentists perceive a lack of specific information about herbal medicine during their academic training and from professional sources in dentistry. Therefore, professional behavior and the practice of phytotherapy in dental clinics seem to reflect personal experience with general health rather than formal education and scientific knowledge on the subject. The implementation of scientific initiatives can help solve the evidence-to-practice gap.