Summary: One of the most conservative treatment methods to correct or improve the color of teeth is bleaching. This study describes the preclinical experience with laser-activated bleaching agent for treatment discolored teeth. The study is comparing three laser systems, halogen-light unit and chemical action agents to check the time and quality of bleaching process. The purpose of the study is to evaluate the effect of various laser techniques for bleaching teeth in office vital whitening. The method of chemical oxidation results in a 2–3 shade change in one treatment. The halogen-light units, Alexandrite laser (750 nm), and Er:YAG received the same effect and shorter time of bleaching process. The local overheating of chemical bleaching agent was visible after Er:YAG laser activation. Slight surface modification after bleaching process was detected in SEM. It was found that selective laser radiation can decrease the time of bleaching without the surface modification.

        Key words: dentistry – laser – bleaching