Primary teeth with infected root canals are a common problem, particularly in patients where the infection has reached the peri radicular tissues .~Among the pastes used in the pulp therapy of primary teeth with pulp necrosis, zinc oxide and eugenol paste has been a reference in dentistry since 1930. Endodontic treatment using zinc oxide and eugenol paste has shown satisfactory clinical and radiographic results, requires mechanical chemical preparation before filling root canals.~The main difficulties of endodontic treatment of primary molars are related to the anatomical complexity of the root canals and the long time needed to carry out the treatment. The additional difficulty involved in diagnosing root resorption is a limiting condition for determining the actual working length and instrumentation.~Other pastes have been studied, such as those containing antibiotics in their composition, thus dispensing with root canal instrumentation (such as lesion sterilization and tissue repair using triple antibiotic paste in treatment of non-vital primary molars.~Lesion sterilization and tissue repair using triple antibiotic paste has relevant clinical and radiographic success rates in treatment of non-vital primary molars.
The aim of this study is to evaluate the clinical and radiographic success of Lesion Sterilization And Tissue Repair [ LSTR] antibiotic paste versus Zinc Oxide and Eugenol pulpectomy in the treatment of non-vital primary molars.