TOPIC: DENTAL CARIES
🌟 IMPORTANT POINTS TO REMEMBER
🔹Interproximal Caries: Interproximal caries begin 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.
🔹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 a vertical dimension of 1.0–1.5 mm.
🔹Moderate Interproximal Caries: These lesions involve more than the outer half of the enamel, but radiographically they do not extend into the dentinoenamel junction.
🔹Advanced Interproximal Caries: The carious lesion spreads laterally when it reaches the dentinoenamel junction. It forms a mushroom- or arrow-shaped radiolucent appearance radiographically with its base on the dentinoenamel junction.
🔹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.
🔹Occlusal Caries: These are also called pit and fissure caries. Early stages of carious lesions 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 are radiographically visible only after the decay has reached the dentinoenamel junction. The radiographic evidence of occlusal caries at this stage is a radiolucent fine shadow just under the dentinoenamel junction.
🔹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 ’.
🔹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.
🔹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.
🔹Root Caries (cemental caries): The radiographic appearance of root caries is defined as a saucer-shaped or scooped-out radiolucent area around the cementoenamel junction.
🔹Secondary Caries is a primary caries developing at the margins of the restorations.
🔹Residual Caries are the demineralised tissue that is left during cavity preparation.
🔹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.
🔹Rampant Caries: Rampant caries is an advanced and severe type of 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.
🔹Radiation Caries: Xerostomia (dry mouth) develops in these patients. Radiographically, it appears as a dark radiolucent shadow appearing at the necks of teeth most obvious on mesial and distal aspects.
📌 MULTIPLE CHOICE QUESTIONS (MCQs)
💡Enamel is composed of
a. 95% mineralised tissue, 4%water and 1% inorganic component
b. 90% mineralised tissue, 5% water and 5% inorganic component
c. 93% mineralised tissue, 4% water and 3% inorganic component
d. 95% mineralised tissue, 1% water and 4% inorganic component
Answer: a
💡The principal aetiological agent in the commencement and progression of caries is
a. Salmonella
b. Streptococcus mutans
c. Candida albicans
d. None of the above
Answer: b
💡Fibre-optic transillumination (FOTI) has been used since
a. 1970
b. 1977
c. 886
d. 1917
Answer: a
💡During FOTI, the demineralised area appears as
a. Lighter
b. Darker
c. Brown hue
d. All of the above
Answer: a
💡 Different radiographic appearance, such as line shape or flame shape is seen in
a. Occlusal caries
b. Nursing bottle caries
c. Root caries
d. Interproximal caries
Answer : d
💡Caries-susceptible zone is having vertical dimension of
a. 1.0–1.5 mm
b. 0.5–1.5 mm
c. 1–2 mm
d. 2–2.5 mm
Answer: a
💡Radiographically interproximal caries appear as
a. Funnel shaped
b. Scooped shaped
c. Saucer shaped
d. Mushroom- or arrow-shaped radiolucency
Answer : d
💡Narrower shadow which is apparent radiographically on the images of sound teeth below or sometimes above the occlusal enamel may be due to
a. Shear effect
b. Mach band effect
c. Background density effect
d. Darkening effect
Answer: b
💡Saucer-shaped or scooped-out radiolucent area around CEJ is seen in
a. Cervical burnout
b. Root caries
c. Occlusal caries
d. Secondary caries
Answer: b
💡Widespread superficial lesion, circumferential lesions and dark pigmentation of teeth are seen in
a. Radiation caries
b. Rampant caries
c. Root caries
d. Occlusal caries
Answer: a
💡 Radiation caries is caused by irradiation of
a. Salivary gland
b. Enamel
c. Enamel and dentin
d. Oral mucosa
Answer : a