This clinical study will look at whether a plant-based essential oil called "Melissa officinalis" (lemon balm) can help reduce fear and stress in children during dental treatment. Children between 6 and 10 years old who need a mandibular injection for a pulpotomy or pulpectomy will be invited to participate. They will be randomly assigned to one of three groups: one group will receive aromatherapy with *Melissa officinalis* from brand A, another group will receive the same essential oil from brand B, and a third group will receive the usual behavioral management used in pediatric dentistry, but without aromatherapy.

The essential oil will be diffused in the dental room so that the child can gently inhale the aroma starting a few minutes before the injection and throughout the procedure. The study team will measure the child's dental anxiety using a child-friendly questionnaire with drawings of faces, observe pain behaviors during the injection, and record the child's own rating of pain with a faces scale. Heart rate and oxygen saturation will also be monitored as objective signs of stress. The goal is to find out whether "Melissa officinalis" aromatherapy is a safe, simple, non-invasive way to make dental visits less stressful and more comfortable for children, and whether there are meaningful differences between the two commercial products.

This is a single center, three arm, parallel group, randomized controlled trial in pediatric dental patients. Participants will be randomized in equal proportions (1:1:1) to one of three groups using permuted blocks, with allocation concealed in sequentially numbered, opaque, sealed envelopes prepared by an independent investigator. Due to the olfactory nature of the intervention, blinding of operators is not feasible; however, outcome assessors who record anxiety, pain scores, and physiological measures will be distinct from the operator and will remain unaware of group allocation until data analysis.

All clinical procedures will be performed by a single calibrated pediatric dentist using a standardized protocol that includes topical lidocaine 10% spray, inferior alveolar nerve block with lidocaine 2% with epinephrine 1:100,000, and subsequent pulpotomy or pulpectomy as indicated. Behavioral management techniques (tell-show-do, positive reinforcement, age appropriate language, and modeling when needed) will be applied in all groups, with the control group receiving only these non pharmacological strategies and no aromatherapy.

Inclusion Criteria:

• Children aged 6 to 10 years at the time of enrollment.
• Male or female pediatric patients in good general physical and mental health.
• Require mandibular local anesthesia (inferior alveolar nerve block) for pulpotomy or pulpectomy of at least one primary molar.
• No previous experience with dental local anesthesia.
• Behavior classified as "positive" or "negative but accepting" (categories 2 or 3) according to the Frankl Behavior Rating Scale during the initial examination.
• Ability of the child to understand simple verbal instructions appropriate for age.
• Parent or legal guardian able and willing to sign written informed consent.
• Child willing to provide verbal assent to participate in the study.

Exclusion Criteria:

• History of previous dental local anesthesia.
• Presence of dental emergencies (e.g., acute infection, severe pain, or swelling) requiring urgent treatment.
• Known diagnosis of neurological, psychiatric, developmental, or behavioral disorders that may interfere with cooperation or with the assessment of anxiety and pain.
• Systemic diseases or medical conditions (American Society of Anesthesiologists [ASA] physical status III or higher) that increase procedural risk or preclude participation according to the investigator's judgment.
• Current acute upper respiratory conditions, such as common cold, rhinitis, sinusitis, or nasal allergy that could alter the sense of smell or breathing comfort.
• Known allergy, hypersensitivity, or adverse reaction to Melissa officinalis, other Lamiaceae plants, essential oils, or components of the products used in the study.
• Use of anxiolytics, antidepressants, sedatives, or other psychotropic medications within the last 30 days.
• Behavior rated as definitely negative (Frankl category 1) or definitely positive (Frankl category 4) at baseline.
• Inability of parents or guardians to understand the study information or provide informed consent.
• Participation in another clinical trial within the previous 30 days.

It has not yet been determined whether individual participant data (IPD) collected in this study will be made available to other researchers. The decision will depend on institutional policies, ethical committee recommendations, and future data-sharing agreements established after completion of the study.

Due to the olfactory nature of the intervention, blinding of operators and participants is not feasible. Therefore, only the principal investigator and the outcome assessor will be blinded to group allocation. The operator performing the dental procedures and managing the aromatherapy device will be aware of the assigned intervention, due to the practical characteristics of the olfactory exposure. However, the individuals responsible for data analysis and for evaluating anxiety, pain, and physiological outcomes will not know which intervention each child received, in order to minimize assessment bias.