Periodontal Anatomy – Gingival sulcus

The gingival sulcus is an area of space which is located between a tooth and the surrounding gingival tissue. It is lined by the sulcular epithelium. In Latin, sulcus translates to groove. The depth of the sulcus is confined apically by the gingival fibers of the connective tissue attachment and coronally by the free gingival margin. In health patients, the sulcular depth is typically 3 mm or less. This means it can be easily cleaned with a toothbrush and floss.


The Dentogingival tissues contain many components, which includes the enamel or cementum of the tooth and the connective tissue which supports the epithelia such as the junctional epithelium. It also contains the gingival epithelium and the sulcular epithelium. While the teeth are erupting, the junctional epithelium is developed. This takes place when the reduced enamel epithelium is merged with the oral epithelium. The reduced enamel epithelium then forms the first junctional epithelium, which firmly attaches to the enamel. In some cases, when there is a gingival recession, the junctional epithelium will actually attach to the cementum.

The non-keratinized stratified squamous sulcular epithelium is thicker compared to the junctional epithelium. It attaches coronally to the junctional epithelium. However, is not attached to the tooth’s surface. The term gingival sulcus, which may also be called gingival crevice, is used to define the space located between the surface of the tooth and the sulcular epithelium. The sulcular epithelium is continuous with the gingival epithelium at the free gingival margin. The attached gingivae and the free gingivae are both included in the gingival epithelium.

The junctional epithelium is a stratified and thin epithelium which attaches to the tooth’s surface. In comparison, the epithelium of the gingival sulcus is stratified squamous and thicker non-keratinized. The presence of Rete Pegs, which may be prominent epithelial ridges, can also be found in the gingival epithelium. Which is a stratified squamous, thick and para-keratinized epithelium.

Basic Periodontal Examination

The Basic Periodontal Examination (BPE) is a quick and straightforward testing method. It is used to systematically screen a patient’s gingival and periodontal health. A goal of the examination is to determine the next steps which are required to assess and treat the patient.

Physiological Immune Surveillance

Following the supra-gingival oral hygiene cleaning, plaque biofilm can quickly collect at the gingival margin. It can also eventually enter the gingival sulcus. The junctional epithelium, located at the base of the gingival sulcus, allows plaque bacteria to enter the gingival connective tissue. This occurs through the large spaces located between epithelial cells of the junctional epithelium. Inflammation often occurs as a result.

In cases where the sulcular depth is chronically greater than 3 mm, routine oral hygiene care at home may not be adequate for properly cleaning the full depth of the sulcus. A sulcular depth of this size can allow the accumulation of food debris and microbes, which can ultimately form a dental biofilm. This presents a danger to the periodontal ligament (PDL) fibers which connect the gingiva to the tooth. When the accumulated microbes are left undisturbed in a sulcus, they can penetrate and kill the delicate soft tissue and periodontal attachment fibers. This process can lead to the deepening of the sulcus, gum recession, destruction of the periodontium, mobility of the teeth, and ultimately tooth loss. The term periodontal pocket is used to describe an abnormally deep gingival sulcus.