Abstract—Optical coherence tomography (OCT) has magnetized substantial notice in biomedical optical imaging since it can reveal the inner structures. Gingival is a soft tissue that surrounds a tooth. In dentistry, the depth of the gingival sulcus reveals clinical diagnostic criteria for periodontal tissue status. We propose an algorithm for measuring the gingival sulcus in the OCT 2D cross-sectional images and verified the algorithm using OCT systems with three different wavelength bands. Periodontal tissues of six healthy individuals, among them maxillary and mandibular incisors and posteriors, were taken. We have obtained a clear comparison of quantitative and qualitative measurements, and to evaluate gingival sulcus non-destructively. Additionally, commercial Sobel and Canny operators primarily used, were compared with the proposed algorithm to confirm reducing sensitivity to noise and speckle in OCT images.