Deep carious lesions are a dental disease widely spread among population of all ages. From clinical point of view, they have little symptoms and go unnoticed by the patients a long time, until they provoke dental pulp inflammations. If diagnosed and treated properly, the tooth can be treated conservatively with certain techniques of pulp vitality preservation. An important role in this process plays the innate capacity of regeneration of the pulp-dentine complex and the enhanced stimulating properties of new biomaterials used in dentistry. The aim of this clinical case report is to describe the clinical manifestations and the diagnostic algorithm used in deep caries and to establish a clinical guideline of treatment of deep carious lesion with a calcium silicate hydraulic cement.