Introduction. Deep caries is treated using Stepwise technique with subsequent application of calcium hydroxide filling (Base.it, Spident). Mineral trioxide aggregate (ProRoot MTA, Dentsply) is used in the treatment of deep caries, inducing pulp cell proliferation and high-strength tissue formation.  Aim of the study. To evaluate the success rate of modern techniques in the treatment of deep caries.  Materials and methods. The study was based on the treatment of 18 patients diagnosed with deep caries. Half of the patients were treated with Stepwise technique using calcium hydroxide, while mineral trioxide aggregate was used to treat other patients. The operative protocol was performed at a single visit: X-ray, professional teeth cleaning, vitality tests, isolation of the operative field, cavity preparation, applying the medicated and insulating filling, applying the final filling and control X-ray.  Results. To carry out a correct and successful treatment of deep caries it is important to establish the right diagnosis. Compliance with all stages of clinical and paraclinical examination will allow to minimize diagnosis errors. Treatment entailing compliance with all stages increases the chance of preserving dental vitality. Each method of treatment needs to be staged and assessed over time. Periodic control increases the rate of success and prevents the occurrence of complications.  Conclusions. The study results demonstrate that the treatment of deep caries by using mineral trioxide aggregate has a higher success rate as it induces pulp cell proliferation, cytokine release, formation of very high-strength tissue, and synthesis of dentin interface that resembles hydroxyapatite. The treatment of deep caries with Stepwise technique using calcium hydroxide shows a lower success rate due to the fact that calcium hydroxide does not offer a sealed adaptation to dentin, it is cytotoxic in cell cultures and reparative dentin is characterized by "tunnel defect".