Class on the use of radiology resources in endodontics.
In this first class we will discuss the basics of radiology, tips for developing and obtaining correct radiographs, analysis of errors during technique and development, conventional and digital radiographs, and the relevance of radiographic examination for diagnosis and planning, treatment, and proservation.
Relevance of the radiographic examination
Endodontic diagnosis and planning
Radiology in endodontics is the resource that provides the greatest amount of information, both as an auxiliary exam in diagnosis and for planning the access surgery. For this purpose, at least two radiographs should be taken with different horizontal angulations, and in some cases it is also necessary to vary the vertical angulation, especially for dissociation between apex and radiolucent images in the periapical region.
When investigating the pulp state, the presence of caries and restorations and their relationship to the pulp chamber should be observed. However, the radiolucent or radiopaque image itself observable on radiographs can be located clinically on the buccal or lingual surfaces. One should therefore be aware that the size of the image or its proximity to the camera is only an aid to diagnosis, and the history and clinical data obtained previously complement the images for a decision.
In order to observe the periapical state, the thickness of the periodontal ligament and the presence of bone rarefaction both in the apex region and adjacent to the root should be carefully observed. Thickening of the ligament or radiolucent images around the root may be indicative of bone resorption resulting from pulp inflammatory processes or periapical tissues. The presence of root resorption should also be investigated. These changes range from the characteristic image of apical rounding, typical of teeth submitted to orthodontic treatment, to irregular images accompanied by bone resorption, as in the case of external and cervical resorption, and rounded images inside the root canal in internal inflammatory resorption.
In cases of cracks or fractures, observation can be extremely difficult, depending on the position of the fracture line. In cases where the fracture line is in the buccal-lingual direction, there are greater possibilities of detection. For the planning of the access surgery, one must pay attention to the dimensions of the pulp chamber, noting the deposition of secondary and restorative dentin and pulpal nodules, which can cause difficulties in locating the canals.
An interproximal radiograph often provides a better image and can also be used for this purpose. Observation of the furcation dimensions can also be useful as an aid in finding the entrance of difficult to reach canals. Special attention should be paid to cases with a history of previously accessed teeth, looking for damage to the furcation, fractured instruments, or foreign bodies. The absence of a quality radiograph in these cases is even more important, since it serves as legal and juridical proof of the previous intervention. The anatomy of the root canals should also be carefully observed for changes, presence of additional canals and curvatures that can make treatment very difficult.
Treatment.
During the endodontic treatment, radiology in endodontics is extremely useful in its various phases. With digital technology this interaction has become even more effective and ergonomics facilitated due to the possibility of immediate observation of the exam on the monitor attached to the chair. The exam is used during access surgery, to guide the opening and location of the canals, in odontometry, to determine the working length, in the cone test, to observe its fit after preparation and irrigation, to check the quality of the filling, and as a final exam, after cervical sealing and placement of provisional restoration. There are, therefore, at least five takes in a conventional treatment.
Proservation.
Radiographic examination is, together with clinical examination, the main tool for proservation after endodontic treatment, both in teeth without periapical changes and in teeth with periapical lesions or after para-endodontic surgery. In cases of treatment in teeth with normal periapical structures, an image of a hard lamina is expected to form around the apex, indicating tissue repair by hard tissue formation. Radiographic examinations accompanied by clinical examination should be performed 3 and 6 months, 1, 2, 3 and 4 years after treatment.
