Aim: To evaluate the clinical outcome of 'Lesion Sterilization and Tissue Repair' (LSTR) therapy for endodontic treatment of primary teeth.
Methodology: A mixture of metronidazole, ciprofloxacin, and minocycline (3Mix) in ointment (macrogol mixed with propylene glycol: MP) or in a root canal sealer was used to disinfect infected root canals of 56 patients aged 4-18 years. Out of a total of 87 primary teeth, 81 cases had physiologic root resorption. A total of 54 radiolucent periradicular lesions were present. The root canals were not prepared before or after disinfection. 3Mix medicament (3Mix-MP/3Mix-sealer) was placed at orifices of root canals or on the bottom of pulp chambers, and then sealed with glass-ionomer cement and further reinforced by a composite resin inlay prepared using a direct method and cemented with resin.
Results: In all cases, clinical symptoms such as gingival swelling (52 cases), sinus tracts (22 cases), induced dull pain (3 cases), spontaneous dull pain (26 cases), and pain on biting (46 cases) disappeared after treatment, although in four cases clinical signs and symptoms were finally resolved only after retreatment using the same procedures. Thus, gingival abscesses and fistulae, if present, disappeared after a few days. Successor permanent teeth erupted without any disorders, or were found radiographically to be normal and in the process of eruption. All the cases were evaluated as successful. The mean function time of the primary teeth was 680 days (range: 68-2390 days), except for one case in which the successor permanent tooth was congenitally missing.
Conclusion: Primary teeth with periradicular lesions with or without physiologic root resorption were treated successfully by the LSTR endodontic therapy.