Effect of Silver Diamine Fluoride (SDF) and LED Activation on Residual Caries Activity After Caries Excavation in Class II Primary Molar Cavities"

Dental caries remains one of the most common chronic diseases in childhood, particularly in primary molars where conventional restorative treatment can be difficult due to limited cooperation and treatment-related anxiety. In minimally invasive approaches such as Atraumatic Restorative Treatment (ART), some softened dentin may be intentionally left near the pulp, resulting in residual carious tissue that could remain metabolically active. Preventing this residual activity is critical to ensure lesion arrest and long-term tooth preservation.

Silver diamine fluoride (SDF), especially at 38% concentration, is an established material for caries arrest because of its antibacterial and remineralizing properties. The American Academy of Pediatric Dentistry supports its use as part of minimally invasive dentistry, particularly for young, fearful, or special-needs children. Recent in vitro research suggests that exposure to blue LED light after SDF application may accelerate silver ion precipitation and enhance dentin microhardness, potentially improving the caries-arresting effect. However, clinical data confirming this benefit are limited and inconsistent.

This study aims to evaluate the effect of LED activation on the residual caries activity of SDF-treated Class II primary molar cavities following caries excavation. The research is designed as a non-interventional observational clinical study conducted at the Department of Pediatric Dentistry, Çanakkale Onsekiz Mart University. After caries excavation performed by a pediatric dental specialist, cavities will receive either 38% SDF alone or SDF followed by LED light exposure (470 nm wavelength, 1000-1200 mW/cm² intensity for 20 seconds). All procedures are part of standard clinical practice; researchers will perform only non-invasive fluorescence measurements using the DIAGNOdent device.

Residual caries activity will be recorded at three time points: immediately after excavation (D₁), immediately after SDF or SDF + LED application (D₂), and one week later (D₃). The primary outcome is the change in DIAGNOdent values over time, comparing SDF-only and SDF + LED groups. Secondary outcomes include the influence of cavity size, tooth location, tooth type, and patient sex on these measurements.

Healthy, cooperative children aged 4-9 years with at least one Class II carious lesion in a primary molar that has undergone excavation but not restoration will be included. Children with systemic diseases, allergies to silver, ammonia, or fluoride, pulpal exposure, or infection will be excluded.