Navigating the Biological Shift in Endodontics: Conventional Pulpectomy Versus LSTR Therapy in Minimally Invasive Care

Abstract

Background and Aim: Traditional paediatric endodontics often relies on aggressive biomechanical filing, which can compromise fragile primary root structures. Consistent with Minimal Intervention Dentistry (MID), this study explores an alternative approach centred on localised antimicrobial action and the innate capacity for self-healing. The study aimed to evaluate periodically over 12 months whether an innovative dual-antibiotic drug combination paste (DAP) used in LSTR could serve as a reliable, non-invasive alternative to traditional zinc oxide eugenol (ZOE) pulpectomy for necrotic primary teeth. Materials and Methods: Two hundred children aged 4–8 years with necrotic primary posterior molars were randomly allocated to two equal treatment arms (  each). Group 1 received LSTR therapy using a local application of DAP (ciprofloxacin and metronidazole) placed directly on the pulp chamber floor without radicular instrumentation. Group 2 underwent standard ZOE pulpectomy with thorough mechanical canal filing and obturation. Both groups were evaluated at 3, 6, and 12 months for clinical and radiographic healing according to standardised Coll and Sadrian criteria. Pearson's chi-square ( ) test was used for statistical comparison, with statistical significance set at . Results: At 12 months, clinical success was 96.0% for ZOE and 92.0% for LSTR-DAP, while radiographic success was 85.0% and 80.0%, respectively. Overall composite success was 84.3% in the ZOE group and 79.7% in the LSTR-DAP group. Statistical testing revealed no significant differences between the protocols at any evaluation interval: 3 months ( ), 6 months ( ), and 12 months ( ). These results indicate that the dual-drug LSTR strategy performed comparably to complete root filling during the study period. Conclusion: LSTR using Double Antibiotic Paste may represent a minimally invasive alternative in child-centred endodontics. By avoiding aggressive filing, LSTR removes the risk of file separation associated with canal instrumentation, respects complex primary canal anatomy, may reduce chairside procedural demands, and may reduce anxiety in young patients. LSTR-DAP therefore offers a practical biological approach that may reduce reliance on invasive mechanical procedures.