Dental Caries Question And Answers

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Dental Caries Important Notes

1. Types of caries

  • Pit and Fissure caries
    • It occurs in pits and fissures
    • It is represented as a cone with a base towards DEJ and an apex towards the enamel surface
  • Smooth surface caries
    • It occurs in the unclean proximal surfaces
    • The base of the cone is towards the enamel surface and the apex is towards the DEJ
  • Residual caries
    • It is caries that remains in a completed cavity preparation by the operator intentionally or unintentionally
  • Forward caries
    • When the caries cone in enamel is larger than that of dentin
  • Backward caries
    • When the spread of caries along the DEJ exceeds caries in contagious enamel and caries extends into the enamel from DEJ
  • Root/senile caries
    • Occurs on the tooth that has been exposed to the oral environment
  • Recurrent/secondary caries
    • It occurs at the borders or underneath the restorations
  • Acute/rampant caries
    • The lesion is light-colored and infectious
  • Chronic/slow-caries
    • The lesion is discolored and fairly hard

2. Composition of GIC

Powder:

  • Silica 3540%
  • Alumina 2030%
  • Aluminum fluoride 1.52.5%
  • Calcium and sodium fluorides 2025%
  • Lanthanum, strontium, and barium in traces

Liquid:

  • Polyacrylic acid 45%
  • Water50%
  • Itaconic acid, maleic acid, tricarballyic acid 5%
  • Tartaric acid traces

3. Accelerators and retarders of ZOE cement

Accelerators

  • Zinc acetate
  • Alcohol
  • Water
  • Glacial acetic add

Retarders

  • Cooling of glass slab
  • Glycerine
  • Olive oil
  • Increasing liquid powder ratio

4. Hybrid or resin-modified GIC

  • BISGMA and TEGDMA are added to GIC powder and HEMA to liquid
  • They are usually light-cured, less technique-sensitive, and may be finished at the time of placement
  • The properties are superior to GIC
  • They are recommended for class V restorations and class I and II in primary teeth

5. Compomer

  • It is a combination of composite and GIC
  • Glass particles are partially silanated and are added as fillers in the composite resin
  • There is no water in the reaction
  • The properties are inferior to composites but superior to GIC and resin-modified GIC

6. Cermet

  • Glass and metal powders were sintered at high temperatures and made to react with liquid
  • It improves fracture toughness and wear resistance and maintains aesthetics

7. Sandwich or bilayered restorations

  • It uses GIC as a liner under composite restoration
  • It increases the retention form as GIC bonds to the tooth and the composite
  • Fluoride content reduces secondary caries.

Dental Caries

Dental Caries Long Essay

Question 1. Enumerate various tooth-colored restorative materials. Give manipulation, indication, and advantage of silicate.

Answer:

Various tooth-colored restorative materials:

Restorative Materials:

  • Glass ionomers
  • Composites
  • Fused porcelain
  • Acrylic resins
  • Silicate cement

Manipulation:

  • Powder/liquid ratio 1.6g/4ml
  • Dispensed on a thick, cool, dry glass slab
  • Divide it in 2/3 increments
  • Mix with agate spatula in a folded manner to obtain a homogenous mass
  • Mixing time 1 minute

Indications:

  • For anterior restoration

Advantages:

  • An anti-cariogenic property
  • Tooth color matching ability
  • Ease of manipulation

Read And Learn More: Operative Dentistry Short And Long Essay Question And Answers

  • The coefficient of thermal expansion is approximately similar to enamel
  • Good insulator
  • Its compressive strength is higher than other cement

Dental Caries Short Answers

Question 1. Buccal Object Rule/Slob/Clark’s rule.

Answer:

Buccal Object Rule:

  • A standard radiograph is taken
  • Shift the cone medially/distally
  • Take a second radiograph
  • If the object is seen on the same side, the object is placed over the lingual side
  • For object localization

Question 2. Caries detecting dyes.

Answer:

1. Dyes for enamel caries:

  • Procion Staining is irreversible
  • Reacts with nitrogen and hydroxyl groups
  • Calcein Bounds with calcium
  • Zyglo ZL22 Visible by UV illumination

2. Dyes for dentin caries:

  • Infected and affected dentin layers are present
  • Basic Fuschia in propylene glycol stains only the infected dentin

Dental Caries Viva Voce

  1. Double inverted cone type of penetration of dental caries is seen in smooth surface caries
  2. Pit and fissure lesions are represented by the base of the cone facing each other
  3. The cervical to-contact area is the common site for proximal caries
  4. Smooth surface caries is mainly caused by streptococcus mutans
  5. Patients with salivary levels of streptococcus mutans above 106 CFU/ml are considered at high risk for dental caries
  6. Remineralization of carious lesions occurs at a pH above 5.5
  7. Streptococcus mutants and lactobacillus are most strongly associated with the onset of caries and active progression of cavitated lesions
  8. Root caries is initiated by A.viscosus
  9. The surface zone of enamel caries is unaffected by caries attack
  10. The Dentinoenamel junction is the least resistant to caries
  11. Increased powder in zinc phosphate cement decreases the setting time and solubility and increases strength and film thickness
  12. Zinc polycarboxylate is the first cement to show adhesion with tooth structure
  13. pH of zinc polycarboxylate liquid is 1.7
  14. Mechanical properties of ZOE cement can be improved by adding alumina to the powder and orthodoxy benzoic acid to the liquid
  15. GIC lacks toughness, and wear resistance and cannot withstand high stress
  16. ZOE and silicate cement have high solubility and disintegration rate
  17. GIC and silicophosphate have low solubility
  18. Resin cement is the least soluble in the oral cavity
  19. The working time of zinc polycarboxylate is 25 min
  20. The working time of zinc phosphate is 5 min.

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