Microlekkage

Microlekkage (also spelled microleakage in English) refers to the diffusion of fluids, bacteria, enzymes, or ions through microscopic gaps at the interface between a dental restoration and tooth structure, or through defects within a restorative material. The term is most commonly used in dentistry to describe pathways that allow oral substances to penetrate despite an apparently intact restoration.

Causes include polymerization shrinkage of resin-based materials, thermal cycling in the oral environment, occlusal loading, and inadequate bonding or moisture control during placement. Marginal gaps, porosity in the material, and degradation of adhesive layers over time also contribute to microlekkage.

Consequences can range from dentin hypersensitivity and marginal discoloration to secondary caries and pulpal irritation. Over time, microlekkage can compromise the seal at margins, potentially accelerating decay and leading to restoration failure.

Measurement and evaluation of microlekkage are typically conducted in laboratory settings. Common methods include dye penetration tests, fluid filtration, and bacterial leakage models. Imaging techniques such as micro-computed tomography (micro-CT) can visualize gaps, though clinical relevance varies.

Prevention focuses on meticulous placement techniques, effective isolation, and appropriate material selection. Using bonding systems with reliable performance, minimizing polymerization shrinkage, and ensuring proper finishing and polishing of margins help reduce microlekkage. Regular clinical monitoring remains important to detect signs of leakage and address them promptly.