Dental caries l Oral radiology MCQs for dental students

 Radiographic Interpretation of Dental Caries l Oral radiology MCQs for dental students 

Important points to remember in Interpretation of Dental Caries

1. Dental caries is a destructive process that causes decalcification of enamel, destruction of enamel and dentin, and cavitation of teeth.
2. To detect dental caries, careful clinical examination and interpretation are necessary.
3. Dental images allow the dental professional to identify carious lesions that are not visible clinically.
4. Caries appears radiolucent on a dental image. Of all the radiolucent lesions that can be seen on a dental image, dental caries is seen most frequently.
5. The dental professional must be con dent in the use of interpretation methods to identify dental caries and to recognize factors that influence caries interpretation (e.g., errors in technique and exposure).
6. Dental caries may involve any surface of the tooth crown or root. The appearance of dental caries can be classified according to the location of the caries on the tooth. Caries involving interproximal, occlusal, buccal, lingual, and root surfaces may be seen on dental images.
7. On a dental image, the appearance of interproximal caries can be classified as incipient, moderate, advanced, or severe, depending on the amount of enamel and dentin involved in the caries process.
8. On a dental image, the appearance of occlusal caries can be classified as moderate or severe, depending on the amount of enamel and dentin involved in the caries process.
9. Buccal and lingual carious lesions are difficult to detect on dental images because of the superimposition of normal tooth structure. Instead, these lesions are best detected clinically.
10. Root surface caries involves cementum and dentin and is easily detected clinically. On a dental image, root surface caries appears as a cupped-out radiolucency below the cemento-enamel junction.
11. On a dental image, other appearances of dental caries include recurrent caries, which appears as a radiolucency adjacent to an existing restoration, and rampant caries, which affects numerous teeth.
12. On a dental image, conditions that may be confused with dental caries include cervical burnout, restorative materials, attrition, and abrasion.
13. Interproximal caries: Interproximal caries begins just below the contact point, and it has a small notched radiolucent appearance on the radiograph. Clinically, there is a white spot lesion which is slightly roughened due to demineralisation.
14. Incipient interproximal caries: The carious lesion often forms a classical V-shaped or triangular-shaped radiolucent appearance at the initial phase. Radiographically, this caries-susceptible zone has vertical dimension of 1.0–1.5 mm.
15. Moderate interproximal caries: These lesions involve more than the outer half of the enamel, but radiographically they do not extend into the dentinoenamel junction.
16. Advanced interproximal caries: The carious lesion spreads laterally when it reaches the dentinoenamel junction. It forms mushroom- or arrow-shaped radiolucent appearance radiographically with its base on the dentinoenamel junction.
17. Severe caries: The lesions that penetrate radiographically more than half of the dentine and are coming closer to the pulp chamber are called severe lesions.
18. Occlusal caries: These are also called pit and fissure caries. Early stages of carious lesion in a fissure are hidden from the naked eye because carious lesions develop at the base and lateral walls of the fissure. The occlusal caries is radiographically visible only after the decay has reached the dentinoenamel junction.
19. The radiographic evidence of occlusal caries at this stage is a radiolucent fine shadow just under the dentinoenamel junction.
20. Mach-band effect: Sometimes, a similar but narrower shadow is apparent radiographically on the images of sound teeth below or sometimes above the occlusal enamel. This is an optical illusion which is called ‘Mach band’.
21. Background density effect: In this illusion, the perceived brightness of the object being observed is related to its background. A band of increased opacity between the carious lesion under restorations and the pulp chamber is another significant sign of occlusal caries.
22. Facial, buccal and lingual caries: These are also called smooth surface caries. The radiographical forms of these lesions depend on their locations and dimensions. They may be round, oval or semilunar.
23. Root caries (cemental caries): The radiographic appearance of root caries is defined as saucer-shaped or scooped out radiolucent area around the cementoenamel junction.
24. Secondary caries is a primary caries developing at the margins of the restorations.
25. Residual caries is the demineralised tissue which is left during cavity preparation.
26. Arrested caries: Arrested carious lesion in dentine has a yellow to dark-brown colour; its surface is hard and smooth as it is polished. Radiographically, these arrested carious lesions appear as small radiolucent areas.
27. Rampant caries: Rampant caries is an advanced and severe type of the carious lesion, and it affects numerous teeth in the dentition at the same time radiographically, there are severe carious lesions affecting many of the teeth.
28. Radiation caries: Xerostomia (dry mouth) develops in these patients. Radiographically, it appears as dark radiolucent shadow appearing at necks of teeth most obvious on mesial and distal aspects.