Abstract: During the complex pathogenesis activities caused by periodontal disease, the tooth root surface undergoes a numerous changes in physical and chemical structure, but also becomes cytotoxic due to the release of bacterial toxins that are embedded in the cementum of the tooth root. The main goal of periodontal therapy is to eliminate the infection and achieve healthy periodontal environment by removing bacterial deposits of dental plaque, dental calculus and the presence of subgingival concrements and endotoxins from the root surface. The ultimate goal of all periodontal procedures is to make the treated root surface biologically compatible with the host's periodontal tissues and to enable proper healing of the periodontium. During the initial periodontal treatment, mechanical debridement is performed on the periodontally compromised root surface to eliminate all calcified deposits (supra- and subgingival concrements), as well as bacteria and their endotoxins to restore the biological compatibility of the root to the disease. There are two basic therapeutic modalities in periodontology-conventional and laser-assisted therapy. Er: YAG is most common used laser that works in the field of infrared wavelength (2,940 nm). Due to its high absorption in water and hydroxyapatite, several studies have shown the effectiveness of this laser in the ablation of hard and soft tissues and its bactericidal effects with little or no pain in clinical application confirm the numerous advantages of this laser. Er: YAG laser is one of the most spectacular types of laser that can be used in periodontal therapy. Its effectiveness in removing the softened and pathologically altered parts from cement and in smoothing the root surface has been proven in vitro studies. The latest scientific evidence suggests that the use of Er: a YAG laser wavelength in the treatment of chronic periodontal disease is equivalent to ultrasound and manual instrumentation of periodontal pockets. Taking into consideration the complex pathological changes, as well as the complexity of reparative and regenerative processes conditioned by the surface interface of the hard wall of the periodontal pocket, the aim of this presentation was to evaluate the morphological and chemical characteristics of tooth cement after application of different periodontal therapeutic modalities. The results of the conducted SEM analysis indicate that after conventional treatment there is advanced, while in laser treated areas there is moderate surface alteration. Based on the results, it can be concluded that after the laser-assisted therapy, the surface roughness as a component of the topographic texture of the cement is very similar to that of healthy teeth. Also, there is a significantly greater reduction in the thickness of the cement after the conventional treatment compared to the laser assisted periodontal therapy. It can be concluded that the root surfaces after the laser-assisted therapy show a greater morphological and chemical similarity with healthy root surfaces than the root surfaces treated with conventional therapy.