In this lecture, we will go through how to X-ray an implant. To X-ray an implant correctly, is essential for making a correct diagnosis. In this X-ray, you can see that the X-ray are parallel to the threads, giving you a good overview of the bone level and all the components. While on this image, the threads are not sharp. Readjusting the tube, reveals a gap on the right implant, suggesting a misfit. But note that only the threads are sharp on the right implant. Readjusting the tube again, gives sharp threads on the left implant, with a gap visible now, while the gap disappeared on the right implant. Sometimes, there's a need to take one image per implant. If you only would have taken the first image, we would have thought there is a misfit. With both images, we now suspect a loose bridge. So, how can we take a correct image? We can elaborate with an X-ray cone and the sensor. The significance of the inclination of the X-ray cone. To take the perfect image, the X-ray cone should be 90 degrees to the implant, like in this picture. If we do this, we'll get the perfect image with sharp threads. If we would take an image from below, like in this set-up, we will get sharp threads on the right side of the implants. This depends on that the X-rays will follow the threads upwards on the right side on the implant, while going against them on the left side. The X-rays will follow the threads on the right side. If we take an image from above, X-rays will follow the threads on the left side, going down instead, giving an image with sharp threads on the left side. It doesn't matter if the implant is in the upper jaw, or in the lower jaw. It still will give the same results. This picture is taken from above. If you simulate an X-ray on these two screws, the threads will be sharp on the left side. Make yourself a rule, like “LARB”. If you have sharp threads on the left side, the tube has been taken much from above. If you have sharp threads on the right side, you have the tube much from below. So let's go through the significance of the tilt of the sensor. Now we know how to adjust the tube, how about the sensor? First, a perfect image as a reference, again. You have sharp threads on both sides. Now we'll tilt the sensor in one direction. It's still resulting in sharp threads. If we're tilting even more to the other side, you have still sharp threads on both sides of the implant. The only thing that happens, is the implant appears the longer, the more we tilt the sensor. Meaning that when radiographing implants, the tilting of the sensor is secondary importance. We're counting the threads, not the millimeters in the implants. When taking X-rays with a digital sensor, the contrast is of importance. This radiograph is taken with the wrong angulation, and much too dark. It looks like there is a lot of bone missing. Sometimes there's a need of several images to radiograph everything we needed. In this case, with the correct exposure, everything looks fine. If we want to examine the apical region of an implant, there's no need for the threads to be sharp.
