junctionalepitelet

Junctionalepitelet, more commonly referred to as junctional epithelium (JE), is a specialized, non-keratinized epithelium that forms a seal at the tooth–gum interface. It lines the gingival sulcus and surrounds the tooth at the cemento-enamel junction, contributing to the barrier between the oral environment and the underlying connective tissue.

The JE originates during tooth eruption from the reduced enamel epithelium and becomes a continuous band around the tooth. It attaches to the tooth surface through a specialized internal basal lamina and multiple hemidesmosomes, providing a relatively loose but effective seal that differs from the surrounding oral epithelium in structure and turnover.

In health, the JE is thin and has a rapid turnover compared with other oral epithelia, enabling remodeling as the gingiva adapts to growth and wear. It serves as a protective barrier and participates in immune surveillance, allowing limited passage of leukocytes to respond to bacterial challenges while shielding the periodontal connective tissue from direct exposure to the oral environment.

Clinical significance arises from the JE’s role in periodontal disease. In periodontitis, the JE migrates apically along the root surface, leading to the formation of periodontal pockets and attachment loss. The integrity and function of the JE influence disease progression and healing after therapy. Around dental implants, a junctional epithelium–like structure also forms a seal at the implant–gingiva interface, but its attachment biology can differ from that of a natural tooth.

Research on the JE focuses on adhesion mechanisms, turnover dynamics, and host response, with implications for periodontal therapy and implantology.