When a penetrating caries affects a temporary tooth and endodontic treatment is required, certain differences exist that the dentist must take into account. The anatomy of the temporary tooth differs from that of a permanent tooth and certain precautions must therefore be taken at the time of opening the pulp chamber. The principal difference in the endodontic treatment of a temporary tooth is that this must be obturated with a reabsorbable material in order for it to be reabsorbed together with the roots and not interfere with the eruption of the permanent tooth. In general, the material chosen for this purpose is zinc oxide-eugenol. When the process only affects the pulp of the chamber, partial pulpotomy is performed with formocresol (22).