This study aimed to assess the clinical and radiographic success of lesion sterilization and tissue repair (LSTR) therapy with different antibiotic combinations, focusing on evaluating whether the alternative combination of clindamycin instead of minocycline is as effective as the standard 3Mix-MP formulation.

All the clinical procedures were carried out by one clinician with 2 years of clinical experience in pediatric dentistry under rubber dam isolation and local anesthesia via mandibular nerve block. (Maxicaine Fort Ampoule, VEM, Turkiye). After the removal of carious tissues, an endodontic cavity was prepared, and infected coronal pulp tissue was removed up to the canal orifices via a sterile round steel bur. A sterile round steel bur was then used to prepare a medication cavity 2 mm deep and 1 mm wide. The root canals were not instrumented, and only the access cavity was irrigated with a 2.5% NaOCl solution. In cases where hemostasis could not be achieved, a sterile cotton pellet soaked in 5% NaOCl was placed in the pulp chamber and left for 1 minute. Once hemostasis was achieved, the endodontic cavity was dried using a sterile, dry cotton pellet. Pastes were then applied to the medication cavity and covered with a glass ionomer cement (Nova Glass II F, Imicryl, Turkiye) and a stainless steel crown (Kids Crown, Shinhung, Seoul, Korea) at the same visit. Clinical and radiographic evaluations were performed at 1, 3, 6, 9, and 12 months. During follow-up, the teeth were assessed on the basis of the following clinical criteria: pain, dentoalveolar abscess and/or fistula, and tooth loss. The radiographic criterion was periapical radiolucency.

Inclusion Criteria:

• Spontaneous pain
• Pain on percussion
• The presence of abnormal or pathological mobility
• The presence of a sinus tract or dentoalveolar abscess
• Widening of the periodontal ligament
• Periradicular radiolucency
• Evidence of external and/or internal resorption.

Exclusion Criteria:

• Who required infective endocarditis prophylaxis
• Who had used antibiotics in the two weeks prior to treatment
• İndividuals allergic to the medications used in the study
• Teeth with pulp floor perforation
• Advanced internal and/or external root resorption
• Root canal obliteration
• Excessive bone loss in the furcation area involving the permanent tooth follicle
• Teeth with severe coronal destruction, nonrestorable.