Inhalation of Lavender Essential Oil for the Management of Anxiety and Pain During Dental Procedures: A Randomized Controlled TrialABSTRACT
Objective: To evaluate the lavender essential oil effects on pain and anxiety in dental patients.
Material and Methods: Forty patients, aged 18-60 years, undergoing dental procedures were randomly assigned to lavender essential oil (experimental group; n=20) or negative control (n = 20). In the essential oil group, participants inhaled pure lavender essential oil under supervision 5 times, 15 minutes before the dental procedure, directly from the bottle held at a distance of 15 cm. In the negative control group, participants inhaled five times, under supervision, a hydroalcoholic solution directly from the bottle held at a distance of 15 cm, 15 minutes before the dental procedure. Pain was assessed with the Visual Analog Scale (VAS) and anxiety with the Dental Anxiety Scale (DAS).
Results: Baseline anxiety ranged from mild (6-10) to moderate (11-15), with no spontaneous pain (score 0). Both groups reported mild treatment-related pain (VAS: 1.2 experimental vs 1.7 control; p > 0.05). The experimental group showed significantly greater anxiety reduction post-treatment (p < 0.05).
Conclusion: Lavender inhalation positively modulates pain perception and significantly reduces anxiety, suggesting a cost-effective adjunct in routine dental practice.
Keywords:
Anxiety; Dental Anxiety; Aromatherapy; Analgesia.
Introduction
Anxiety is increasingly recognized as a major global health burden. According to the World Mental Health Report, the prevalence of anxiety disorders has risen by 25% globally in recent years [1]. Dental treatment-induced anxiety remains a significant barrier to care, affecting 3-43% of the population. This psychophysiological state activates the central nervous system, elevating blood pressure and heart rate while potentiating pain perception during dental interventions [2].
Despite pharmacological approaches remaining standard for anxiety management, their undesirable side effects [3] have driven growing interest in non-pharmacological alternatives. In the United States, expenditure on complementary therapies reached $30.2 billion annually according to the National Center for Complementary and Integrative Health in 2021 [4], with projections suggesting global market growth to $5 trillion by 2050 [5,6]. This trend reflects demand for natural solutions with comparable efficacy but improved safety profiles.
Aromatherapy is a non-pharmacological, complementary, and alternative therapy that proposes using of essential oils to relax and control the mind and body through aromatic compounds with neurological and physiological effects [3].
The use of lavender essential oil for therapeutic purposes is an ancient practice [2] and has emerged as particularly notable due to its broad spectrum of therapeutic effects and its designation by the U.S. Food and Drug Administration (FDA) as ‘Generally Recognized as Safe’ [7]. The literature already consolidates its effect in reducing anxiety and stress in dental patients due to its sedative properties [2]. Additionally, it is known as a mood enhancer, anxiolytic, insect repellent, and possesses antimicrobial and epithelializing effects [8]. It has also demonstrated activity against various bacteria, fungi, and viruses present in the oral cavity, helping to control infections, reduce bacterial growth, and combat bad breath [6].
Another promising action highlighted and explored is the effect of lavender essential oil, specifically its role in pain control as an analgesic ally during dental procedures [8]. However, with these new findings, questions arise regarding protocols and safety in its use, the caution required in the modus operandi, and the responsibility of professional supervision [6], given the possibility of allergic reactions and interactions with other medications or dental treatments.
The olfactory route is essential for lavender essential oil absorption [9] due to two systemic action mechanisms: volatile molecules enter the circulatory system via nasal mucosa or lungs, then act on target organs, and olfactory perception is transmitted through inhalation and acts directly on the central nervous system.
Inhalation of lavender essential oil during dental consultations and procedures contributes to a calmer and more comfortable environment, aiding in patient well-being and improving the experience during treatment. Nevertheless, studies in controlled environments are of utmost importance for understanding the real contribution of essential oils not only in enhancing the dental environment experience but also in human physiology as part of a treatment.
The study objective is to assess the efficacy of Lavandula angustifolia essential oil in managing dental anxiety (primary outcome) and procedure-triggered pain (secondary outcome).
Material and Methods
Ethical Clearance
This study was approved by the Research Ethics Committee of University of Taubaté, Protocol No. 6.651.994 and is registered as CAAE 71448423.4.0000.5501 and conducted in accordance with Brazil’s National Health Council Resolution No. 466/2012 [10] and international good clinical practice guidelines (ICH E6) [11]. All participants received written and verbal explanations regarding the study’s objectives, methodology, potential benefits, and risks.
Sampling and Procedures
A sample size calculation was performed to determine the number of participants required for this study. For this purpose, results from previous studies [2,12] that used the same endpoints (VAS and DAS) were utilized. Using a statistical significance level of 95% (α = 0.05) and power of 90%, an independent samples t-test was applied. To account for potential loss to follow-up during the study, a 10% safety margin was adopted, resulting in a minimum of 20 participants per study group.
Forty patients (aged 18-60 years) undergoing dental procedures were randomly allocated into two groups. Randomization was performed using sealed opaque envelopes to ensure allocation concealment. In the essential oil group (n = 20), participants inhaled pure lavender essential oil (Lavandula angustifolia, doTERRA Global Corporate Headquarters, Pleasant Grove, UT, USA) under supervision 5 times, 15 minutes before the dental procedure, directly from the bottle held at a distance of 15 cm. In the negative control group (n = 20), participants inhaled five times, under supervision, a hydroalcoholic solution directly from the bottle held at a distance of 15 cm, 15 minutes before the dental procedure. All inhalation procedures were administered by the same operator to ensure consistency. The essential oil used was lavender (Lavandula angustifolia, doTERRA Global Corporate Headquarters, Pleasant Grove, UT, USA), with information on the manufacturer, purity, absence of additives, and quality certification (including GC-MS analysis) available from the supplier. Pain was assessed using the Visual Analog Scale (VAS), while anxiety levels were measured through the Dental Anxiety Scale (DAS).
Dental Anxiety Scale (DAS)
This scale consists of four simple questions and was applied before two consecutive dental appointments for both groups. The points corresponding to the answers were summed, and patients were classified as follows: a) Until 5 points = low anxiety; b) 6 to 10 points = mild anxiety; c) 11 to 15 points = moderate anxiety; and d) 16 to 20 points = extremely high anxiety.
Visual Analog Scale (VAS) for Pain
A 10-point pain intensity scale [13] was applied after dental appointments for both groups. To measure patients' pain perception before and after procedures, a Visual Analog Scale (0-10) was used, with 0 indicating no pain and 10 meaning the worst possible pain.
Data Analysis
After complete tabulation of the data obtained in the present study, statistical analysis was performed using SPSS software, version 13.0 (IBM Corp. Armonk, NY, USA), adopting a significance level of 95% (α = 0.05). As the variables were qualitative and non-parametric in nature, the Mann-Whitney U test was applied for independent groups, whereas the Wilcoxon signed-rank test was used for dependent groups.
Results
When applying the VAS to assess pain before the dental procedure, no patients reported pain, meaning all baseline scores were 0 (Table 1 and Figure 1), fulfilling the inclusion criteria. The results showed that the lavender essential oil group had lower numerical pain scores after dental treatment (mean pain score of 1.2, ranging from 0 to 3) than the control group (mean pain score of 1.7, ranging from 0 to 4). Moderate pain was only experienced by participants in the control group. However, no statistically significant difference was observed between the groups (Figure 2).
Frequency of pain scores (0 - 10) per individual measured by VAS before and after dental procedures and inhalation of lavender essential oil or negative control.
Level of pain experience before and after dental treatment in the lavender essential oil and control groups.
Comparison of the effect of lavender essential oil versus control group on pain experience associated with dental procedures in both groups.
A questionnaire to measure pre-appointment anxiety (DAS Questionnaire) was administered to both groups (control and lavender). According to Table 2, patients in the lavender essential oil group were classified as moderately anxious (Mean = 14.5). In contrast, patients in the control group exhibited only mild anxiety (Mean = 9). Therefore, there was initially a statistically significant difference between the groups, where patients who would inhale lavender essential oil showed higher anxiety in the waiting room compared to the control group (Figure 3). Despite higher baseline anxiety levels in the lavender group (p < 0.001), after dental treatment, both groups (Figure 3) achieved similar (p > 0.05) low anxiety levels (mean anxiety score 2 in the lavender group vs. 1.1 in the control group).
Frequency of anxiety scores (0-4) per individual measured by the DAS scale before and after dental procedures and inhalation of lavender essential oil or control group.
Anxiety levels before and after dental treatment in the lavender essential oil and control groups use same categories applied in the statistical analysis; i.e., 0 (DAS scores 0 - 5) low anxiety; 1 (DAS scores 6 - 10) mild anxiety; 2 (DAS scores 11 - 15) moderate anxiety; 3 (DAS scores 16 - 20) extremely high anxiety.
Discussion
The use of essential oils, such as lavender essential oil (Lavandula angustifolia), as adjuncts in dental treatment has gained attention due to their potential anxiolytic and analgesic effects, aligning with the growing demand for integrative and less invasive therapies [6]. This study evaluated the efficacy of lavender essential oil inhalation in reducing anxiety and pain in patients undergoing dental procedures, comparing its effects to a control group that inhaled a hydroalcoholic solution. The results demonstrated that, although there was no statistically significant difference between groups regarding pain, the lavender group exhibited a lower mean pain score (1.2 vs. 1.7 in controls). Additionally, anxiety, initially higher in the lavender group (mean 14.5 vs. 9 in controls), was significantly reduced post-procedure, reaching levels comparable to the control group.
Dental anxiety is a well-documented phenomenon that, unfortunately, contributes to treatment avoidance [2,14]. Lavender aromatherapy emerges as a complementary strategy rooted in ancient practices. Civilizations such as the Egyptian, Greek, and Roman cultures already used plant extracts to promote physical and mental well-being [7]. Hippocrates, the ‘father of medicine’, advocated aromatic baths for health balance [6], while in World War I, essential oils were employed in wound treatment [7].
Studies such as those by Kritsidima et al. [12] and Kim et al. [15] corroborate that lavender may be as effective as pharmacological anxiolytics, with fewer adverse effects. Furthermore, Atsumi et al. [16] demonstrated its ability to reduce salivary cortisol, a stress marker. The neurobiological mechanisms of lavender explain its efficacy: its active compounds, linalool and linalyl acetate, modulate the limbic system (emotion regulator) and enhance GABA activity, an inhibitory neurotransmitter associated with relaxation [17].
Dental procedures triggered mild to moderate self-reported pain. Although between-group differences in pain perception did not reach statistical significance, a trend toward lower pain scores was observed in the lavender group (mean VAS score: 1.2) compared to controls (1.7).
Arslan et al. [2] observed lower pain in dental extractions with lavender. This effect may be linked to modulation of serotonin and dopamine, neurotransmitters involved in pain-inhibitory pathways [17]. Additionally, lavender induces endorphin release (natural analgesics) [7] and reduces physiological stress parameters, such as blood pressure and heart rate [2], but it is essential to use the olfactory route for the correct lavender effect [9]. Kim et al. [15], analyzing 37 clinical trials, found greater effects with inhalation compared to massage or oral administration. Collectively, these results suggest that lavender’s hypnotic effects depend on olfactory stimulation rather than direct bloodstream entry [18].
A rarely addressed but critical issue is the risks of essential oils. While less severe than pharmacological risks, they warrant professional guidance to mitigate potential adverse effects. Reported concerns include: flammability, safety in elderly/children (oral ingestion risks), dermatitis, phototoxicity, oral toxicity, and ocular safety [6].
Lavender aromatherapy is a low-cost, easily applicable intervention compatible with Brazil’s National Policy on Integrative and Complementary Practices (PNPIC/SUS) [19]. Its adoption is particularly relevant in Brazil, where 9.3% of the population suffers from pathological anxiety, and dental avoidance is common [20]. Non-pharmacological strategies (e.g., aromatherapy, hypnosis, audiovisual distraction) are safe alternatives, especially for children and phobic patients [3].
Although in the present study a sample size calculation had been done, future studies with large samples are required. Despite randomization, environmental factors in the waiting room may have influenced baseline anxiety levels in one group, which should be managed in further studies. Teaching clinics should also be equipped with smaller, quieter waiting rooms, as typically seen in private dental practice offices. Future research should explore the synergistic effects of essential oil combinations and condict larger randomized trials with standardized protocols.
Conclusion
Lavender essential oil inhalation may be an effective tool for reducing anxiety and pain in dental patients. These findings support the incorporation of complementary strategies, such as aromatherapy, into multidisciplinary approaches to improve patient comfort and anxiety management in dental setting.
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Financial SupportNone.
Acknowledgements
The authors acknowledge the University of Taubaté for their valuable support and resources during this research.
Data Availability
The data used to support the findings of this study can be made available upon request to the corresponding author.
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Edited by
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Academic Editor: Alessandro Leite Cavalcanti
