Introduction:
Dental radiography is mainly utilized for the study of endodontic, periodontal, or maxillofacial assessment purposes like the assessment of pulp and root canal morphology, the status of alveolar bone, and within the inter-dental region along with detection of periapical pathologies and crown or root fractures.
Dental radiology for most of the cases in endodontics is especially useful for endodontic root canal treatment or for pre-treatment evaluation of roots and root canal morphology, for calcified canals, root curvatures, periapical lesions or abscesses, for working length determination during RCT, and for monitoring of the quality and extent of root canal obturation material post-treatment and its healing in a few days.
Correct use of appropriate imaging technology along with the correct interpretation by the radiologist or dental surgeon by following the principle of ALARA (As low as reasonably achievable) and with cost-effectiveness is what forms the crux of today's dental radiology. Two-dimensional imaging uses both periapical and panoramic radiographs that are most commonly utilized in dental practice.
How Are Dental Imaging Techniques Classified?
Broadly, dental imaging techniques in dentistry can be classified as:
1. Intraoral and extraoral radiography.
2. Analogue and digital radiography.
3. Ionizing and non-ionizing radiographic imaging, and as
4. Two-dimensional (2-D) and three-dimensional (3-D) imaging.
This terminology is used more commonly by the dentist to highlight the differences and for educating the patient about the technologic upgrade and benefit mainly.
However, there are certain limitations accompanying two-dimensional radiographs, which can be definitively reduced or have less scope for technical error by three-dimensional imaging techniques. These are mainly cone-beam computed tomography (CBCT), magnetic resonance imaging (MRI), and ultrasound. However cone-beam computed tomography is the most preferred by dentists in the maxillofacial region.
From the simple intra-oral periapical X-rays, advanced imaging techniques like computed tomography, cone beam computed tomography, magnetic resonance imaging, and ultrasound have also been used, with CBCT being the most adopted technique in modern dentistry.
What Is the Difference Between a Conventional and a Digital Radiography?
In modern dentistry, the switching from analog to digital radiography has made dental radiography simpler and faster, which has additional benefits like image storage and manipulation (brightness, contrast or cropping of the obtained image), image retrieval software, etc.
The conventional or the long-time use of film-based radiography requires the presence and proper care or maintenance of the darkroom. Also, the chemical handling in the darkroom may be associated more often with processing or technical errors that depend upon the radiologist who's developing the x-ray. These disadvantages for developing and fixation are overcome by the now frequently used and preferred advent of digital radiography. This revolution in recent decades is the result of innovation by researchers and technicians alike for speeding up the image acquisition process. Also, the development of networked systems of computing is beneficial and ideal for the dual purpose of image retrieval and image transmission.
Mainly there are three types of digital radiography systems used and commonly available for dental imaging that uses this technology of:
A. CCD-Charge-Coupled Device (direct system);
B. CMOS-Complementary Metal Oxide Semiconductor (direct system);
C. PSP-Photo-stimulable phosphor (indirect system).
Why Is Digital Imaging Preferred Over the Conventional Imaging Techniques?
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The advantage of digital radiography over the conventional film radiography is that the radiation dose is almost reduced up to 80% according to researchers given the obvious benefits of processing time within a short duration and the quick acquisition of the image post radiography, it is the most preferred way for more than a decade.
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Also, the elimination of the darkroom and its processing chemicals for developing the film and fixation coupled with the technical errors, if any, by the operator or those errors associated with improper darkroom maintenance or mishandling of the chemical solutions is all avoided altogether by the digital imaging adopted in modern dental clinics and hospitals.
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Digital radiography also allows manipulation of the image produced for enhancing the contrast, density, sharpness, and image orientation. Also, the radiation exposure to the patient and the operator is much reduced.
What Are the Types of Dental Radiographs Based on Views?
1. Occlusal Radiograph: An occlusal radiograph displays a large segment of a dental arch that cannot be viewed on a periapical radiograph, such as a cyst. It helps to locate supernumerary or impacted teeth, any foreign bodies possibly in the jaw region, and salivary stones (sialoliths) and ductal stones of the salivary glands.
2. Bitewing Radiographs: Also known as interproximal radiographs, are used to commonly evaluate inter-proximal surfaces of the upper and lower teeth when the patient bites on the film with both surfaces simultaneously. This is useful for diagnosing dental caries.
3. Extra-oral Radiographic Views: The extra-oral radiographic examination in oral medicine includes the frequent study through panoramic radiographs, posteroanterior or even the lateral skull view, Water's view, the posteroanterior view, lateral cephalometric view (based upon the indication by the dental surgeon). Extraoral radiographs will help the dentist study the jaws and skull in precision (especially the landmarks of importance). The monitoring of growth and development of craniofacial structures skeletally and its use frequently indicate the location of impacted wisdom teeth, and large pathological lesions or the evaluation of the temporomandibular joint make extraoral radiographic views an idealistic study.
4. Cephalometric Radiographs: They help in identifying the entire side of the head and neck region and for evaluating the spatial relationships between craniodental and craniofacial structures. This radiography is mainly of value in comparison and contrast of growth and development in the dental and skeletal structures (done commonly by the orthodontist before, during, and after orthodontic treatment). The benefit is the correct acquisition of patient, soft tissue profile, and with comparatively lesser X-ray exposure to the other techniques.
5. Computed Tomography: This is the most advanced and upgraded element of modern dentistry that is preferred by dental clinicians. This technique or method employed is the use of fan-shaped X-ray beams with multiple exposures around an object to reveal its internal structures in 3-dimensional view. These 3-D views of the object help the clinician to view morphologic features and pathology in three dimensions. CBCT's varied application in all fields of dentistry includes the detection of oral and maxillofacial or dental and developmental cysts, tumors, infections, anomalies, traumatic injuries, etc., in the orofacial region. Due to its high-resolution advantage, it is also extensively used for dental and osseous disease evaluation of the temporomandibular joints and treatment planning prior to dental implants.
Conclusion:
The recent advances in imaging technologies have revolutionized dental diagnostics and treatment planning. Also, the correct use of newer radiographic techniques and the recent upgrades in technology can definitely help to detect dental and maxillofacial pathologies from an early stage and provide a good long-term prognosis for the patients affected.
