Dental fluorosis is a developmental enamel defect characterized by discoloration and altered enamel appearance, which may negatively affect dental esthetics and patient satisfaction. Conservative treatment approaches, including enamel microabrasion and minimally invasive chemical treatments, have been proposed to improve the appearance of affected teeth while preserving tooth structure. However, evidence comparing the effectiveness of these treatment modalities remains limited.

This randomized controlled clinical trial aims to compare the effectiveness of Antivet treatment and Opalustre enamel microabrasion in improving the esthetic appearance of mild enamel fluorosis/discolored enamel affecting anterior teeth. Eligible participants with mild enamel fluorosis will be randomly allocated to receive either Antivet treatment or Opalustre enamel microabrasion in a 1:1 ratio. Tooth color will be objectively assessed before and after treatment using a spectrophotometer based on the CIELAB color system (L*, a*, and b* coordinates), and the overall color difference (ΔE) will be calculated. The primary outcome is the change in tooth color following treatment, while secondary outcomes include changes in individual CIELAB color coordinates. The findings of this study are expected to provide evidence regarding the comparative effectiveness of these minimally invasive treatment modalities for the esthetic management of mild enamel fluorosis.

Dental fluorosis is a developmental enamel defect resulting from excessive fluoride intake during enamel formation. It is characterized by varying degrees of enamel opacity, discoloration, and surface irregularities that may compromise dental esthetics and negatively affect patients' quality of life. Conservative treatment approaches are preferred for managing mild fluorosis because they preserve sound tooth structure while improving esthetic appearance. Among these approaches, enamel microabrasion has been widely used to remove superficial enamel discolorations through the combined action of hydrochloric acid and abrasive particles. More recently, minimally invasive chemical treatment systems, such as Antivet, have been introduced as alternative treatment options for improving enamel discoloration while minimizing the removal of sound enamel.

Although both treatment modalities have demonstrated favorable clinical outcomes, evidence directly comparing their effectiveness in improving tooth color remains limited. Therefore, this randomized controlled clinical trial was designed to compare the esthetic outcomes of Antivet treatment and Opalustre enamel microabrasion in the management of mild enamel fluorosis affecting anterior teeth.

Eligible participants presenting with mild enamel fluorosis involving permanent maxillary or mandibular anterior teeth were randomly assigned in a 1:1 allocation ratio to receive either Antivet treatment or Opalustre enamel microabrasion. All treatment procedures were performed according to the manufacturers' recommendations under rubber dam isolation to ensure adequate moisture control and protection of the surrounding soft tissues.

The primary outcome measure was the change in tooth color following treatment, objectively assessed using a spectrophotometer based on the Commission Internationale de l'Éclairage (CIELAB) color system. Color coordinates (L*, a*, and b*) were recorded before and after treatment, and the overall color difference (ΔE) was calculated to quantify treatment-induced color improvement. Secondary outcome measures included changes in individual CIELAB color coordinates, including lightness (L*), red-green chromaticity (a*), and yellow-blue chromaticity (b*).

Statistical analysis included paired-samples and independent-samples t-tests to evaluate within-group and between-group differences. Because baseline differences in chromaticity were identified, analysis of covariance (ANCOVA) was performed using baseline color values as covariates to provide adjusted comparisons between treatment groups. Statistical significance was established at a two-sided α level of 0.05.

The findings of this study are expected to provide high-quality clinical evidence regarding the comparative effectiveness of two minimally invasive treatment modalities for improving the esthetic appearance of fluorosis-affected anterior teeth. The results may assist clinicians in selecting conservative treatment approaches that optimize esthetic outcomes while preserving enamel structure.

Inclusion Criteria:

1. Patients aged from 20-35 years old.
2. Patients free from any systematic diseases.
3. Patients agreed to the informed consent and are compliant to the follow-up periods.
4. Teenagers and young adult patients refrained from tobacco products throughout the current study period.
5. Patients with hypominerlized maxillary and mandibular ante- rior teeth (incisors and canines) were included.
6. Teeth with Degree 1 (mild) according to the Wetzel and Reckel scale.

Exclusion criteria

1. Patients with special health care needs or any systemic disease that may delay normal healing.
2. Patients having bad oral hygiene.
3. Patients who could not be committed to the follow-up period.
4. Patients suffering from untreated, periodontal diseases
5. Participants with caries lesions or defective restorations in the anterior teeth.
6. Sensitive and fractured teeth.
7. Participants who had a history of dental bleaching.
8. Patients participating in other dental studies.
9. Patients suffering from hypoplasia, amelogenesis imperfecta, dentinogenesis imperfecta, tetracycline stains, fluorosis, or badly broken and missing teeth due to MIH.

Due to the nature of the interventions, operator blinding was not feasible. However, the examiner responsible for outcome assessment and the biostatistician performing the statistical analyses were blinded to treatment allocation throughout the study to minimize detection and analysis bias.