Which statement best differentiates microleakage from a marginal gap?

Which statement best differentiates microleakage from a marginal gap?

• A. Marginal gap is a fluid movement through microscopic gaps at margins.
• B. Microleakage is a fluid movement through microscopic gaps at margins; marginal gap is a visible gap at the margin of a restoration.
• C. Microleakage refers to a visible gap at the margin; marginal gap is fluid movement through microscopic gaps.
• D. Microleakage and marginal gap describe different terms for the same phenomenon.

Answer: (B)

Microleakage describes a process: fluids, bacteria, and other molecules move through microscopic gaps at the tooth-restoration interface, often driven by polymerization shrinkage, thermal changes, or occlusal forces. This movement can occur even when the margin appears clinically smooth, because the gaps are too small to see. A marginal gap, on the other hand, is a visible discrepancy at the edge of the restoration—a tangible gap you can detect with a probe or visually. So the best differentiation is that microleakage is about fluid movement through microscopic gaps, while a marginal gap is a visible gap at the margin. In practice, a visible marginal gap can contribute to microleakage, but they describe different phenomena.

Microleakage describes a process: fluids, bacteria, and other molecules move through microscopic gaps at the tooth-restoration interface, often driven by polymerization shrinkage, thermal changes, or occlusal forces. This movement can occur even when the margin appears clinically smooth, because the gaps are too small to see. A marginal gap, on the other hand, is a visible discrepancy at the edge of the restoration—a tangible gap you can detect with a probe or visually. So the best differentiation is that microleakage is about fluid movement through microscopic gaps, while a marginal gap is a visible gap at the margin. In practice, a visible marginal gap can contribute to microleakage, but they describe different phenomena.