NON-SURGICAL RETREATMENT OF THE FIRST MAXILLARY PREMOLAR WITH THREE-ROOT CANAL ANATOMY: A CLINICAL CASE OF “MOLARIZATION” OF THE PREMOLAR.

Background: Endodontic retreatment of teeth with complex root canal anatomy presents considerable diagnostic and therapeutic challenges, particularly when complicated by anatomical variations or intracanal obstructions. “Molarization” of a maxillary first premolar—a rare anatomical variation characterized by the presence of three independent root canals—may significantly complicate retreatment procedures. The presence of an intracanal titanium post further increases technical difficulty and risk. Objective:To describe a diagnostic and minimally invasive nonsurgical retreatment protocol for a maxillary first premolar with a three-root canal system complicated by a titanium intracanal post. Materials and Methods:A 42-year-old male patient presented with pain on biting in tooth 1.4 and was referred for endodontic retreatment. Diagnostic assessment included cone-beam computed tomography (CBCT), intraoral periapical radiographs, and clinical examination under an operating microscope. CBCT confirmed a three-root canal configuration consistent with premolar molarization and revealed the presence of a titanium apical post. Treatment was performed under local infiltration anesthesia (4% articaine with epinephrine 1:100,000) and rubber dam isolation. Ultrasonic tips and micro-diamond burs were used for conservative removal of the titanium post under magnification. Canal patency was established using stainless steel K-files up to size #15. Mechanical preparation was completed with a NiTi rotary system (SoCo Plus) to an apical size of 35. A multi-step irrigation protocol was implemented using sodium hypochlorite, EDTA, and chlorhexidine, with ultrasonic activation to enhance chemicalmechanical debridement. Obturation was performed using gutta-percha with the lateral condensation technique and AH Plus sealer. The titanium post was successfully removed without procedural complications. All three canals were identified, negotiated, and thoroughly disinfected. Results: Postoperative radiographs confirmed dense three-dimensional obturation without voids or material extrusion. At the 6-month follow-up, the tooth was asymptomatic and fully functional. Radiographic evaluation demonstrated satisfactory periapical status and stable obturation. Conclusions:This case illustrates that nonsurgical retreatment of a maxillary first premolar with molarization and an intracanal titanium post can be performed predictably using a minimally invasive approach. The integration of CBCT diagnostics, optical magnification, ultrasonic instrumentation, and a structured irrigation protocol allows safe management of complex root canal anatomy and intracanal obstacles. This strategy provides a reproducible and toothpreserving treatment algorithm for similarly challenging endodontic cases.