Cone Beam CT Scan vs. Traditional Dental Radiographs
We moved to our new location in August 2018 for many reasons, the main one being that we had simply outgrown our 900 square foot remodeled house. It was beginning to feel more like a maze as we struggled to find a place to put each new piece of equipment. And then when we realized that we needed to have an in-house cone beam CT scan in order to deliver the quality of care to our patients that we really desired, we knew we would have to find a larger space. Once we moved, we often heard the same question from our patients. “Why do we need to have a cone beam CT scan when you take traditional dental x-rays?” Good question!
The traditional dental radiographs are usually three different types. The most common one is called the bitewing radiograph. It is generally taken once a year. It is the one that can make your eyes water when you have to bite down on the film! This is a very important diagnostic tool in that it allows the dentist to detect decay occurring between the teeth that is not detectable simply by looking into the mouth. These cavities can be present for years before noticeable to the human eye. With the bitewing radiograph, the cavity can be discovered and addressed before it is large and causing complications with the nerve.
Another traditional radiograph taken in the dental office is the panorex. This is the one where the patient will sit or stand in the machine as it rotates around them. The resultant image is a 2D radiograph of the teeth and jaw structures. This is a useful tool for detecting pathology in the jawbones as well as finding where the wisdom teeth might be hiding. It is generally taken every three to five years.
Another radiograph often taken in the dental office is the periapical radiograph. This is a small radiograph taken of the root tips of the teeth. It is used to detect a dental infection that has permeated through the bone around the roots of the teeth. Such an infection would appear as a black circle around the root tip. It used to be the only tool dentists could utilize to find such infections. Usually driven by a patient’s symptoms of pain, the periapical radiograph (or PAx) would be taken to definitively diagnose necrosis of the nerve, or infection in the nerve causing it to die. However, the frustrating fact about periapical radiographs is that they would often show inconclusive results. A patient would have all the symptoms pointing to nerve necrosis, but the PAx would look normal. Why?
The answer lies in the fact that we were trying to look through all the layers of anatomy. It can be impossible to see through at times. Imagine what a bone looks like. The anatomy of a bone is similar to a column. The inner portion of the column is similar to a swimming pool noodle–spongy yet firm. The outer portion of the column is a very hard, solid, and dense layer, protecting the inner spongy layer. In the jawbone, this inner spongy layer, called the cancellous bone, has the roots of the teeth in it. When a tooth becomes infected, the infection spreads to this bone, causing a hole to form. If the infection is not addressed, this hole in the bone will grow until it has broken through the outer dense layer of bone, called the cortical bone. With a traditional periapical radiograph, the infection can only be seen once it has broken through the outer cortical bone. Therefore, the infection has to be present long enough to form the destruction necessary to break through both layers of bone. However, with the cone beam CT, the infection can be noted while it is present only in the cancellous bone, allowing for much earlier detection and less destruction of the surrounding bone.
So, while traditional dental radiographs are still useful for early detection of cavities, the cone beam CT scan is the state-of-the-art equipment useful for early detection of infection. If the infection is detected early, once it is treated, healing can occur much faster and easier. This makes the cone beam CT scan the standard of care at Origin Dental Wellness. It is an invaluable tool for early detection of dental infections.