Studies have shown that enamel can be modified by pulsed CO₂ laser to form a more acid-resistant substrate. This study evaluated the effects of a 10.6-μm CO₂ laser on enamel surface morphology and chemical composition as well as monitored intrapulpal temperature changes during irradiation. Human teeth were irradiated with fluences of 1.5-11.5 J/ cm², and pulpal thermal as well as chemical and morphological modifications on enamel were assessed. The teeth were submitted to a pH-cycling model, and the mineral loss was determined by means of cross-sectional microhardness. For all irradiated groups, intrapulpal temperature changes were below 3°C. FT-Raman spectroscopy and scanning electron microscopy indicated that fluences as low as 6.0 J/ cm² were sufficient to induce chemical and morphological changes in enamel. Then, for fluences reaching or exceeding 10.0 J/ cm², laser-induced inhibitory effects on demineralization were observed. It was thus concluded that laser energy density in the range of 10.0 and 11.5 J/ cm² could be applied to dental enamel in order to produce chemical and morphological changes and reduce the acid reactivity of enamel without compromising the pulp vitality.