An in vitro study about the influence of temperature on the solubility of deciduous powdered enamel protected by sodium fluoride (0.05%) was made to observe the variation of the weight loss when the tissue was exposed to 0.5 N lactate buffer at pH 4.5. The protective capacity of fluoride to decrease the acid solubility in temporary tooth enamel presumably can be attribute to increase the temperature measured by scale centrigrade.