This study aims to compare the effectiveness of Lesion Sterilization and Tissue Repair (LSTR) with conventional pulpectomy in treating pulpal lesions in primary molars of pediatric patients aged 4 to 10 years. LSTR is a minimally invasive method that uses antibiotic paste to disinfect infected tissue without full canal instrumentation. Children participating in this study will receive either the LSTR technique or standard pulpectomy, and the clinical and radiographic success of both treatments will be evaluated over a 12-month period. The goal is to determine whether LSTR is a safe and effective alternative to pulpectomy in primary teeth.

This is a prospective, comparative clinical trial conducted at Atatürk University, Department of Pediatric Dentistry, Erzurum, Turkey. The study compares two endodontic treatment methods for primary molars with pulpal lesions in children aged 4 to 10 years. A total of 110 primary molar teeth from 98 pediatric patients were included. Teeth were assigned to two main treatment groups: the experimental group receiving Lesion Sterilization and Tissue Repair (LSTR) and the control group receiving conventional pulpectomy. Each group was further divided into two subgroups based on the type of final restoration - stainless steel crown (SSC) or compomer - resulting in four treatment-restoration combinations: LSTR + SSC, LSTR + compomer, pulpectomy + SSC, and pulpectomy + compomer. Restoration type was determined based on patient cooperation and parental preference.

The LSTR group was treated with a combination of ciprofloxacin and metronidazole antibiotics mixed with iodoform-calcium hydroxide paste (Viopex), applied to the canal orifices without mechanical instrumentation. The pulpectomy group received standard chemomechanical canal debridement and obturation with iodoform-calcium hydroxide paste. Both groups were subsequently restored with either SSC or compomer.

Patients were followed up clinically and radiographically at 3, 6, and 12 months. Clinical parameters assessed included spontaneous pain, percussion sensitivity, abscess, fistula, and pathological mobility. Radiographic parameters included periapical and interradicular lesion resolution, internal root resorption, and external root resorption. Overall tooth survival was evaluated using Kaplan-Meier survival analysis and Log-Rank test. The primary objective was to assess whether LSTR achieves similar clinical and radiographic success compared to conventional pulpectomy, and to determine the effect of restoration type on long-term treatment outcomes.

Inclusion Criteria:

• Children aged 4 to 10 years.
• Presence of at least one primary molar with pulpal involvement requiring endodontic treatment.
• Good general health without systemic conditions.
• Signed informed consent from parent or legal guardian.

Exclusion Criteria:

• Children with systemic diseases or immune-compromising conditions.
• Known allergies to any of the materials or antibiotics used in the study.
• Uncooperative behavior preventing dental treatment under normal clinical conditions.
• Teeth with non-restorable crown structure or excessive root resorption.