Assessment of microleakage characteristics of different resin composite materials applied using the conventional and stamp techniques

This study aimed to evaluate the effect of the stamp technique, an increasingly preferred approach in pediatric dentistry, on microleakage when used with different composite resin materials. The physical and chemical properties of composite resins, including filler morphology, filler content, viscosity, and polymerization behavior, play a critical role in marginal adaptation. Therefore, the clinical success of restorations is influenced by both the application technique and the restorative material. The stamp technique has been proposed as a practical alternative in pediatric dentistry due to its ability to reduce operative time, reproduce occlusal anatomy predictably, and shorten chairside time, thereby improving patient cooperation. However, evidence regarding its interaction with different composite materials remains limited. In this in vitro study, 120 sound human third molar teeth were selected, and standardized Class I cavities were prepared. Four different composite resin materials (G-ænial, Nova, Quixfil, and Estelite) were applied using two restorative techniques: the conventional incremental technique and the stamp technique. After restoration, all specimens were subjected to thermocycling to simulate intraoral thermal conditions. Microleakage was evaluated using the dye penetration method, and the composite–dentin interface was further analyzed using scanning electron microscopy (SEM). The results demonstrated that composite type was the primary factor influencing microleakage. Quixfil exhibited consistently low microleakage values irrespective of the application technique. While the overall effect of the stamp technique was not statistically significant, a significant reduction in microleakage was observed when the stamp technique was used with Estelite. In contrast, no significant differences related to application technique were detected for G-ænial and Nova composites. SEM findings supported the microleakage results, showing a more uniform and continuous marginal interface when the stamp technique was combined with low-viscosity composite materials. Within the limitations of this study, the stamp technique alone does not appear to be a decisive factor in reducing microleakage. However, when combined with appropriately selected composite materials, it may enhance marginal adaptation. Material-related properties seem to have a more dominant influence than the application technique itself. Therefore, the stamp technique may be considered a time-efficient and clinically useful option in pediatric dentistry when used with suitable composite resins.