The extraction of a lower molar restored with a definitive crown and a metallic post represents a surgically complex procedure that demands meticulous planning and careful execution in order to avoid unnecessary loss of bone tissue and to preserve future reconstructive options such as implant placement. In such cases, attempting to remove the entire tooth in one piece is not only imprudent but may also result in trauma and significant damage to the alveolar bone, especially when dealing with divergent, curved, or partially ankylosed roots.
The first essential step is the complete removal of the prosthetic crown, which provides direct access to the tooth structure and allows proper assessment of the intracanal metallic post. These posts are often rigidly cemented and may have caused microfractures or weakening of the root structure, making a cautious approach even more critical. Post removal should be performed using high-precision rotary instruments or specialized ultrasonic devices, under ample visualization and with strict protection of surrounding tissues, in order to avoid unnecessary stress or radicular fractures during manipulation.
Once the post is removed, a strategic odontosection of the molar is performed. This technique allows the tooth to be divided into independent segments—typically the mesial root, distal root, and coronal portion. Odontosection not only facilitates the individual removal of each root but also minimizes the need for aggressive luxation or maneuvers that could compromise the alveolar walls. During this step, it is essential to actively protect the soft tissues using retractors, constant irrigation, and instruments that avoid tearing or damaging the remaining periodontal ligament or gingiva.
One of the most critical aspects of this procedure is the accurate control of the depth of the cut, particularly when extending the section from the occlusal surface toward the furcation. Cutting beyond the furcation—due to poor planning or limited visibility—can result in exposure or damage to the interradicular bone or adjacent structures, leading to unnecessary bone loss. To avoid this, a precise radiographic measurement must be obtained in advance, either with high-quality periapical X-rays or, ideally, with a 3D CBCT scan. This assessment helps determine the exact distance between the occlusal surface and the furcation entrance, ensuring that the odontosection remains within the tooth structure and does not encroach on the bone.
Furthermore, it is crucial to control the parameters of the rotary instruments, working at low to medium speeds and with constant and abundant irrigation to prevent bone overheating. Cortical bone is particularly susceptible to thermal necrosis when exposed to temperatures above 47 °C for more than a minute, which can easily occur if high-speed burs are used without proper cooling. Thermal damage to the bone, while often asymptomatic at first, can lead to delayed healing, bone resorption, or implant failure if not prevented.
Once the odontosection is completed and the roots are segmented, they are extracted using minimally invasive techniques. Delicate luxators, thin periapical elevators, or piezoelectric devices are ideal for mobilizing the roots without damaging the socket walls. Conventional forceps should only be used when mobility is already present. In the event of root fracture, extreme care must be taken to avoid cortical perforations, particularly on the buccal or lingual aspects.
This stepwise approach—careful removal of the restoration, precise post extraction, limited odontosection, and root-by-root extraction—allows for optimal preservation of alveolar bone architecture, prevention of soft and hard tissue complications, and leaves the surgical site in excellent condition for either guided bone regeneration or implant placement, if indicated.
Ultimately, this type of extraction should not be regarded as a routine procedure but rather as an advanced surgical act that requires deep anatomical understanding, radiographic planning, proper instrumentation, and a conservative mindset that prioritizes tissue and bone preservation as the therapeutic goal.