Evaluation of Microleakage in Class v Restorations Using Four Different Composite Resin Placement Techniques: An in Vitro Study

Class V restorations are common in restorative dentistry, frequently located at the cemento-enamel junction, where they face increased challenges such as wear, abrasion, and caries formation. Microleakage, the penetration of fluids and bacteria between the restoration and the tooth structure, is a major cause of failure in these restorations. Various methods have been proposed to minimize microleakage, with composite resins being widely used. This study evaluates four different composite resin placement techniques for their effectiveness in reducing microleakage in Class V restorations. Forty extracted human teeth were selected and randomly divided into four groups. Each group underwent restoration using one of the following techniques: horizontal incremental, U-shaped incremental, split incremental, and mat incremental. Microleakage was assessed using methylene blue dye after thermocycling and sectioning the teeth. A stereomicroscope was used to measure dye penetration along the restoration margin. The results revealed that the Mat incremental technique produced the least microleakage, with the majority of specimens exhibiting no dye penetration. The horizontal incremental technique showed the highest levels of microleakage, with many specimens showing dye penetration to two-thirds of the cavity depth. Statistical analysis indicated significant differences between the techniques (p<0.05). The Mat incremental technique is the most effective in minimizing microleakage in Class V composite restorations, followed by the split incremental technique. These findings suggest that these methods may offer greater long-term success and durability for composite restorations in clinical practice.