How can laser be used in dentistry? Using laser in dental care isn't a modern discovery because it has been used from more than 25 years to treat different dental problems. Using laser in dental treatment showed successful results in many cases. It could be used in the following cases : -Cases which need surgical crown lengthening or when the displayed part from gingiva is more than it should be, here we can use laser to do gingivectomy instead of using surgical method with scalpel. -Cases which need biopsy to remove lesions for pathological analysis. -Teeth whitening procedure depending on laser energy to activate whitening agents in whitening material during chemical bleaching. -Caries removal when teeth are simply decayed but it cannot be used in large or previously filled cavities and drilling is still the best in treating cavities. It has been found that using laser in such dental treatments is favorable to many patients because it seems less painful than traditional treatment methods, no anesthesia needed and no bleeding during or after procedure. Due to these advantages using laser in dentistry is still expensive. Laser used in dentistry is classified into : -Soft tissue laser (carbon dioxide or diode laser) which can remove soft tissue gently and quickly with a suitable wavelength. -Hard tissue laser (erbium laser) which can penetrate hard tooth structure (enamel and dentin) with large wavelength.