One of the biggest frustrations for the referral specialist is receiving films that are not of diagnostic quality. It is impossible to accurately schedule or evaluate patients if properly exposed and developed images are not available. Frequently, this necessitates another patient visit - either to the referring Generalist or to the Specialist - just to get a properly angled, well-developed image. This Month's EndoFiles Fax examines some of the most common problems and shows you how to provide the proper radiographic information to allow for the most efficient referral, if it is necessary.
1. Take multiple images of the tooth (or teeth) in question.
Radiographs are 2 dimensional pictures of a 3 dimensional object. Multiple images allow for best visualization of the actual tooth/root anatomy. Whereas radiographic exposure may have been a concern in the past, faster films, better developing solutions, lower KvP machines and digital radiography have all combined to reduce patient exposure. There is no reason why multiple images of a tooth should not be taken. We must explain the limitations of the imaging technology to the patient and make them understand that optimal treatment results come from knowing as much as possible about the anatomy of the area. Note: Pregnancy IS NOT a reason to avoid taking radiographic images. I frequently explain to expectant mothers that the risks of multiple radiographic images (especially with lower KVp or digital images) are far less than the potential harm of waiting for clinical signs that may necessitate administration of systemic antibiotics during pregnancy. Frequently, anatomic structures such as the Mental and Incisive foramina can be confused with periapical pathology. This is especially true when only ONE image is examined. If multiple images (mesial and distal shifted, for example) are also taken, such structures can easily be identified because they will "move" with the shifted films and no longer be as intimately associated with the apex as previously thought.
2. Use appropriately sized films or image sensors
Size 0 and 1 films may be more convenient to use in the anterior areas but their image sizes are very limited. Significant pathology, adjacent anatomical structures and clues will not be able to be seen with many of these smaller sizes. Using them in the posterior areas limits your ability to properly image the case. Whenever possible, use multiple size 2 images, even if they "pinch" a little during film placement. If you must use smaller sizes, use multiple images so that the entire area is properly imaged.
3. Where Pathology is Present, attempt to get all of the lesion on the film, if possible.
Periradicular pathology comes in many forms. Many of them are NOT endodontic in etiology. There is a tendency to see an incompletely imaged periapical area and make a diagnosis on this basis. One example I saw recently was a dentigerous cyst that was misdiagnosed as a lesion of endodontic origin in a virgin mandibular second molar. The dentist saw a large radiolucency encompassing the tooth and immediately suspected an endodontic problem. The tooth was opened and found to be vital. The case was referred to me after the pulpectomy and I suspected that the pulp was not the source of the lesion. I arranged for a Panoramic film and my suspicions were confirmed. The tooth had been opened in error.
4. Take BW radiographs
Patients requiring endodontic diagnosis or treatment often have full coverage restorations of varying vintages. Periapical radiographs (especially in the maxilla) have to be perfectly angled for proper visualization of the crown margins. Rather than struggle with a PA, routine diagnosis should include well-angulated (NOT overlapped) BW radiographs that allow you to see along proximal crown margins and determine whether caries or leakage is occurring. There is no point in performing endodontic treatment on a tooth if we know that the coronal seal is compromised at the start. Patients have the right to know whether their restorations need to be replaced BEFORE endodontic treatment is initiated.
5. Proper Angulation - Use paralleling devices whenever possible
(Thanks to Dr. Joseph Dovgan for the Figs 1& 2. below)
Proper angulation produces undistorted images of teeth that are not overlapped and are without cone cuts.
6. Trace All Sinus Tracts
Sinus tracts (sometimes incorrectly called "fistulas") frequently track far from the site of drainage. Because of this, it is important to trace the sinus tracts to their source with a gutta percha point properly placed into the sinus. In some cases, patients may require a small amount of local anesthetic to do this. Remember to do your pulp tests FIRST (before the anesthesia is administered) otherwise it will be impossible to confirm your suspicions of pulpal necrosis with pulp tests during the same appointment.
7. Arrange for Panoramic films of you don't have a Panoramic Imager
Larger radiolucencies sometimes cannot be completely captured on a single size 2 or larger film image. Sometimes there are more diffuse radiolucencies or suspicion of more generalized osseous involvement. Larger Cystic, Systemic or malignant disease can also manifest itself in generalized bone changes that are best examined with a Panoramic film. For this reason (and prior to initiation of any endodontic treatment) arrangements should be made to properly and completely image all lesions where such suspicions are included in the differential diagnoses. 8. Make sure to properly fix and wash all films. Even properly angulated images can be made useless through careless developing procedures. Endodontic "quick films" (those that are frequently processed using a "chairside" darkroom and hand - dipping technique) can be rendered useless if they are not properly fixed and washed. Endodontic recalls rely on image comparisons. Proper maintenance and cleaning of automatic developing units ensures that the maximum amount of information can be produced, read and stored on each image - and that this information will be available for use in the future. Early digital imaging systems used thermally based printer paper. This paper has an extremely limited lifespan and fades with exposure to light. Every effort should be made to store these images in digital format (on Hard Drives or digitally archived) to preserve image quality and allow for better comparison evaluation on patient recall.