Comparative evaluation of microleakage in composite restorations using different layering techniques: an in vitro study.

Introduction. Resin composites are widely used in restorative dentistry due to their functional and aesthetic advantages. However, contraction stress is still a significant drawback of polymerisation shrinkage, especially in cavities with high configuration factors (C-factors). This could lead to microleakage, marginal gap formation, and adhesive failure. While shrinking cannot be completely eradicated, several solutions have been devised to lessen its impacts and enhance marginal adaptation, such as alternative layering techniques. Aim of the study. To evaluate and compare how various composite layering methods affect microleakage. Material and Methods. Standardised occlusal cavities were created using thirty removed human molars and premolars. Before being used, the teeth were cleaned and stored at room temperature in distilled water. Five groups were randomly selected from the samples, each group restored using a different technique: oblique incremental, horizontal incremental, cusp build-up,” stress-breaking liner” technique with oblique layering, and split-increment technique. After thermocycling, the samples were submerged in 1% methylene blue and 50% silver nitrate dye solution for 24 hours. Microleakage was evaluated using a macro magnification following sectioning. Results. The split-increment group had the lowest microleakage, while the horizontal incremental group had the highest. The horizontal layering technique group showed a statistically significant difference from the other groups. Conclusions. The performance and longevity of composite restorations are greatly impacted by layering techniques. Restorations that are long-lasting and therapeutically successful can be achieved by minimising microleakage and improving marginal adaptation through appropriate selection and application.

DOI: https://doi.org/10.62838/ASMJ.2026.1.11