This study aims to evaluate and compare the clinical characteristics and treatment outcomes of early caries lesions using resin infiltration (Icon) and microabrasion (Opalustre). Early enamel lesions (ICDAS codes 1-2) often present as white spot lesions, which can compromise esthetics and may progress if untreated. This randomized split-mouth clinical trial will be conducted in patients presenting with at least two affected anterior teeth. Each patient will receive both interventions in different teeth, allowing direct intra-individual comparison. Outcomes will be assessed immediately after treatment and at 6 months to determine effectiveness in lesion improvement, esthetic appearance, and patient-related responses. The findings aim to provide evidence for minimally invasive management of early caries lesions.

Early caries lesions, commonly manifested as white spot lesions, represent subsurface enamel demineralization without cavitation. These lesions are frequently observed in patients with plaque accumulation or undergoing orthodontic treatment and may progress if not managed appropriately. Minimally invasive approaches, such as resin infiltration and microabrasion, have been proposed as effective treatment strategies to arrest lesion progression and improve esthetic outcomes.

This study is designed as a randomized split-mouth controlled clinical trial to compare the effectiveness of resin infiltration (Icon, DMG, Germany) and microabrasion (Opalustre, Ultradent, USA) in the management of early caries lesions classified as ICDAS codes 1 and 2. The study will be conducted at Can Tho University of Medicine and Pharmacy Hospital.

Eligible participants will include patients aged 9 years and older presenting with at least two early caries lesions on anterior teeth. A split-mouth design will be applied, where each patient receives both interventions on different teeth, allowing intra-subject comparison and minimizing inter-individual variability.

For the resin infiltration group, the procedure includes enamel conditioning with hydrochloric acid (Icon Etch), ethanol drying (Icon Dry), and application of infiltrant resin followed by light curing. For the microabrasion group, treatment involves the application of hydrochloric acid and abrasive particles (Opalustre) using a rotary instrument under controlled conditions.

Clinical assessments will be performed at baseline (T0), immediately after treatment (T1), and at 6-month follow-up (T2). The study will evaluate changes in lesion characteristics, esthetic improvement, and patient-reported outcomes. Data will be analyzed using appropriate statistical methods to compare treatment effectiveness between the two interventions.

This study aims to provide clinical evidence on the comparative effectiveness of two minimally invasive techniques for early caries management, contributing to improved treatment decision-making in restorative and preventive dentistry.

Inclusion Criteria:

• Patients aged 12 to 18 years
• Presence of at least two early caries lesions (ICDAS codes 1-2) on the labial surfaces of anterior teeth (maxillary or mandibular incisors and canines)
• Patients who are willing to participate and provide informed consent (or consent from parent/guardian for minors)

Exclusion Criteria:

• Teeth that have undergone endodontic treatment at the study site
• Teeth with existing restorations or requiring restorative treatment at the lesion site
• Patients with systemic conditions or oral conditions that may affect enamel integrity or interfere with treatment outcomes
• Patients who are unable to comply with follow-up visits

Outcome assessors evaluating clinical images and treatment results are blinded to the intervention allocation to minimize assessment bias.