The space between the inner aspect of the free gingiva and the tooth. It is normally 1–3mm in depth and deepest interproximally. The epithelium is non-keratinized. The gingiva is attached to the tooth at the base of the gingival crevice by the junctional epithelium beneath which is a band of connective tissue/free gingival fibres. The gingival crevice produces a serum exudate (gingival crevicular fluid) which alters when disease is present.