The Influence of Er:YAG Laser on the Dissolution Rate and Morphology of the Root Cement A scanning electron microscopic study

Lasers can interact with dental tissues inducing changes in tooth characteristics, regarding the surface morphology and elemental composition. The alterations were observed in Calcium, Phosphorus, Sodium, Oxygen and Carbon elements, which influence the resistance and chemical properties of dental hard tissues. The thermal energy used by laser reduces water content of the tissues and as a consequence, the level of oxygen composition decreases after irradiation. Numerous studies had demonstrated its ability to ablate hard-tissues, without any detrimental thermal effects such as cracking or melting for the adjacent tissues. The aim of this article is to present the in vitro effects of Er:YAG laser in comparison with sonic, ultrasonic and manual instruments on the root cement during scaling and root planning, evaluated by scanning electron microscope. The study was conducted on extracted teeth, divided in four groups according to the method used for scaling and root planning. The specimens were analyzed by scanning electron microscopy and the morphological alterations of the cement were evaluated based on a scoring system. Data were statistically analyzed using Mann-Whitney test and the level of significance was set at p<0.05.We noted unfavorable results on the root cement after using Er:YAG laser as craters and cracks induced by heat. There was a greater amount of roughness on the root surface after Er:YAG was used for scaling and root planning compared to manual, sonic and ultrasonic methods. Despite favorable results obtained after the use of Er:YAG laser during periodontal treatment, further clinical studies are necessary in order to determine in which moment of the therapy these methods are most suitable.