Comparison of LSTR and Pulpectomy in Primary Molars of Pediatric Patients (LSTR-PULP)

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.

• LSTR (Procedure): Lesion Sterilization and Tissue Repair (LSTR) is a minimally invasive pulp therapy using ciprofloxacin and metronidazole mixed with iodoform-calcium hydroxide, without canal instrumentation. The access cavity is sealed and restored with SSC or compomer.
• Pulpectomy (Procedure): Pulpectomy includes mechanical canal preparation, irrigation, and obturation using iodoform-calcium hydroxide paste, followed by final restoration with stainless steel crown or compomer.

Primary outcomes

• Clinical Success Rate of Treated Primary Molars [At 3, 6, and 12 months post-treatment]: Clinical success is defined as absence of pain, swelling, sinus tract, and pathological mobility assessed through standardized clinical examination by a pediatric dentist.

Secondary outcomes

• Radiographic Healing Rate of Treated Primary Molars [At 6 and 12 months post-treatment]: Radiographic healing is defined as the resolution of periapical or interradicular radiolucency, and the absence of pathological root resorption progression. Radiographic assessment was performed by evaluating the presence or absence of periapical/interradicular lesions, internal root resorption, and external root resorption on digital periapical radiographs. Note: The Periapical Index (PAI) scoring system was originally planned but was not applied due to the radiographic characteristics of primary teeth and the nature of the lesions encountered; descriptive radiographic assessment was used instead."

Sex: All, ages: 4 Years to 10 Years

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.

• Study Protocol and Statistical Analysis Plan (PDF, 2026-05-28)
• Informed Consent Form (PDF, 2024-08-01)

• Sera DERELİOĞLU, DDS, PhD, Principal investigator, Ataturk University