What term describes leakage of bacteria, food debris, or saliva through the material-tooth interface?

• A. Osmosis
• B. Microleakage
• C. Diffusion
• D. Marginal leakage

Answer: (B)

Microleakage describes leakage of bacteria, food debris, or saliva through microscopic gaps at the interface between the restorative material and the tooth surface. This term captures the idea that even a tight-looking margin can have tiny pathways due to imperfect bonding, polymerization shrinkage, or differences in how the materials expand and contract with temperature changes. Fluids and microorganisms can seep through these microspaces, which is why microleakage is a major concern for sealing ability and longevity of restorations, potentially leading to secondary caries and pulpal irritation. Osmosis and diffusion refer to different, more general processes of movement through barriers, not specifically the leakage along the tooth–material interface. Marginal leakage is a related concept but is a broader or less precise label; microleakage is the standard term that describes leakage through microscopic gaps at the interface.