Enhanced effectiveness of silver diamine fluoride application with light curing on natural dentin carious lesions: an in-vitro study

Abstract

Background: Silver diamine fluoride (SDF) is widely accepted as a dentinal caries arresting agent because of its effectiveness, easy handling, and short working time. When dealing with uncooperative patients, a reduced working time is desired. As SDF has been known to interact with light, the effects of light curing (LC) on SDF have not been investigated. This study aimed to compare mean mineral density difference and surface morphology between 10-and 60-second(s) SDF-applied dentin carious lesions and similarly SDF-treated teeth with additional 20s LC. Methods: Forty primary molar blocks with natural dentin carious lesions were measured for baseline lesion depth and mineral density at baseline using Image-Pro Plus software. Samples were distributed into 4 groups; 38% SDF applied for 1) 10s (10SDF), 2) 60s (60SDF), 3) 10s+LC (10SDF+LC), and 4) 60s+LC (60SDF+LC), then underwent a 7-day bacterial pH-cycling. Dentin carious lesions’ mean mineral density difference was re-evaluated by digital subtraction radiographic analysis. Surface morphology and elemental profile were assessed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The mean mineral density difference of the dentin lesions was analyzed using two-way ANOVA, generalized linear models analysis.Results: Light curing was the only factor affecting the mean mineral density difference (p=0.007). Mean mineral density differences in 10SDF+LC and 60SDF+LC groups were significantly higher than those without light curing (p=0.041 and 0.041, respectively). The 60SDF+LC group showed a significantly higher mean mineral density difference than the 10SDF group (p=0.010), while the 10SDF+LC group was not different from the 60SDF group (p=1.00). Scanning electron microscopy showed denser mineral content layers, which likely were silver and chloride, in 10SDF+LC and 60SDF+LC groups than 10SDF and 60SDF groups, respectively.Conclusion: Shortened application time with light curing enhanced SDF remineralization similarly to a conventional method. This could be valuable for managing dentin caries in young or uncooperative children and special-needs patients by reducing the SDF application time by 50% of the American Academy of Pediatric Dentistry recommendation while maintaining an adequate SDF remineralization effectiveness.