Objective: to evaluate dental leakage in composite resin restorations carried through on the lining with zinc oxide and eugenol in molar deciduous. Methods: For the study, had been used 24 deciduous molars, which had been divided in three groups, in accordance with the moment where the resin restoration was carried through: G1= immediately after de insertion of the IRM, G2= after 48 hours and G3= after 28 days. A occlusal socket was carried through, in all the teeth, with a drill 3018 HL (KG Sorensen). After restored, the teeth had been covered enamel layer and wax, leaving itself around exempts a region of 1,, of the restoration. The teeth had been, then, immersed in rodamina dye 0.5% during 24 hours. After it was removed the enamel and the wax, and the teeth had been washed, dried and cut with a machine of precision cut (Labcut 1010). The specimens had been evaluated in a Stereo Microscope (Olympus SZH 10) and classified by levels of infiltration of 0 the 3. Results: Through the analysis statistics, a significant association was evidenced enters the presence of infiltration and the period where the restoration was carried through. It was observed that in the immediate period dental leakage had a minor and in the period of 28 days a bigger infiltration (p=0.02). Conclusion: It is important that there is not much time between temporary restoration with IRM and final restoration with composite resin to decrease microleakage.