Operative Dentistry Miscellaneous Short And Long Essay Question And Answers

Miscellaneous Long Essays

Question 1. Discuss various restorative materials used to restore Class 2.

Answer:

various restorative materials used to restore Class 2:

Materials Used:

• Composites
• Amalgam
• Direct filling gold
• Metal inlay

1. Composite:

Definition:

• It is a compound composed of at least two different materials with properties that are superior or intermediate to those of an individual component

Composition:

• Organic matrix BisGMA or UDMA
• Fillers Silica, barium. Zinc, Zirconium
• Coupling agents organic silane
• Coloring agents Titanium oxide
• UV Absorber Benzophene
• Initiator Camphoroquinone
• Inhibitor Butylated hydroxyl toluene

Properties:

• High coefficient of thermal expansion
• Composites with higher filler content exhibit lower water absorption
• Wear resistant
• Radiolucent
• Low modulus of elasticity

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• Water solubility 0.51.1 mg/cm²
• Polymerization shrinkage
• Esthetics
• Microleakage
• Biocompatible

2. Amalgam:

• Composition:
  • Alloy:
    • Mercury
    • Silver 40%
    • Tin 32%
    • Copper 30%
    • Zinc 2%
    • Indium traces
  • Mercury:
    • Properties:
      • Initially, a small amount of contraction followed by expansion
      • Amalgam has a maximum compressive and tensile strength
      • Creep It is a time-dependent response
      • It leads to marginal deterioration
      • Amalgam shows tarnish and corrosion
      • Amalgam needs pulpal protection
      • Amalgam transmits temperature changes
      • It has a high coefficient of thermal expansion
      • Microleakage

3. Direct filling gold:

Properties:

• Cohesiveness
• Softness during manipulation
• Malleability and ductility
• Brinell hardness number 25
• Tensile strength 19000 psi
• The coefficient of thermal expansion is 14.4 x 106/°C
• High thermal conductivity
• The density of gold is 19.3 gm/cm³

Types:

• Gold foil:
  • Sheets
  • Gold foil cylinder
  • Gold pellets
  • Platinized gold foil
  • Corrugated foil
  • Laminated foil
• Crystalline gold:
  • Mat gold
  • Mat foil
  • Electrically
• Powdered gold:

4. Metal Inlay:

Definition:

• Inlay is an indirect intracoronal restoration that is fabricated extra orally and cemented in the prepared tooth

Advantages:

• Better reproduction of details
• More wear resistance
• Biocompatible
• Strengthen the weakened remaining structure
• Less chair side
• Less chances of voids
• Easy to polish

Disadvantages:

• Require temporary restoration
• Expensive
• Technique sensitive
• Difficult to repair
• Weak bonding to tooth structure
• Unaesthetic

Miscellaneous Short Essays

Question 1. Interim restoration.

Answer:

Interim restoration:

Objectives:

• Maintain esthetics
• Act as space maintainers
• Allow functioning
• Determine occlusion
• Establish phonetics
• Seal and insulate the prepared tooth
• Prevent passive eruption of the tooth
• Prevent pathologic migration

Requirements:

• Good marginal adaptation
• Optimal strength
• Plaque resistant surface
• Economical
• Easy to manipulate
• Dimensionally stable

Purpose:

• Pulp protection
• Act as a sedative
• Soft tissue protection
• Protect weakened tooth protection
• Maintain the aesthetics

Materials Used:

1. For Intra coronal preparation

• Guttapercha
• Zinc oxide eugenol
• Zinc phosphate
• Zinc polycarboxylate
• Glass ionomer
• Calcium hydroxide

2. For extra coronal

• Polycarbonate crowns
• Aluminum cylinder
• Stainless steel crowns
• Celluloid crowns
• Indirect acrylic restorations

Question 2. Resin Cement.

Answer:

Resin Cement:

Uses:

• For cementation of inlays/onlays
• For cementation of crown and bridge
• For bonding amalgam restoration
• For cementation of orthodontic brackets
• For cementation of endodontic posts

Types:

• Unfilled resin cement
• Filled resin cement

Available Forms:

• Powder and liquid
• 2 paste system
• Single paste with accelerator

Composition:

• Powder:
  •  Resin matrix
    • B1SGMA
    • TEGDMA
  •  Fillersilica
    • Zirconia
  • Coupling agent
    • Organosilane
  • Initiator and activator
• Liquid:
  • Adhesive HEMA:
  •  Initiator:
    • Benzoyl peroxide
• Inorganic fillers:
  • Silica
  • Zirconia
    • Means of Polymerisation:
      • Chemical cure
      • Light cure
      • Dual cure
        • Commercial Names:
          • PanaviaEx
          • RelyX
          • ARC Resin cement

Miscellaneous Short Answers

Question 1. Temporary restorative materials.

Answer:

Temporary restorative materials:

It is restoration given to the prepared tooth for the period between tooth preparation and cementing the restoration

Features:

• Nonirritating
• Esthetics
• Easy to clean
• Maintain periodontal health
• Adequate strength and retention

Question 2. Secondary Dentin.

Answer:

Secondary Dentin.:

• Secondary dentin is formed after the completion of root formation
• The direction of dentinal tubules is more asymmetrical and complicated
• It is formed at a slower rate

Question 3. Tertiary Dentin/Reparative dentin.

Answer:

Tertiary Dentin:

• It is formed as a response to external stimuli
• It is irregular, with cellular inclusions
• Its tubular pattern ranges from an irregular to a tube-lar nature
• Reparative dentin has decreased permeability
• It is formed by secondary odontoblasts which are differentiated from mesenchymal cells of the pulp
• Reparative dentin helps in the prevention of diffusion of noxious agents from the tubules

Question 4. Universal Operator position.

Answer:

Universal Operator position:

• 11 clock is considered a universal operating position

Position:

• The dentist sits behind slightly to the right of the patient and the left arm is positioned around the patient’s head.

Advantages:

• Most areas of the mouth are accessible from this position either using direct/indirect vision

Working Areas:

• Palatal and incisal/occlusal surfaces of maxillary teeth
• Mandibular teeth

Question 5. Transillumination and Magnification.

Answer:

Transillumination:

• Used for detection of caries
• Based on the difference in the refractory index of carious and sound normal tooth
• Carious tooth appears as a dark shadow when compared with the normal tooth

Magnification:

• Devices:
  • Loupes
  • Surgical telescopes
  • Bifocal eyeglasses
• Advantages:
  • Increases visibility of the operating area
  • Easy to perform the delicate procedure
  • Increases operator’s efficiency
  • Protects eye from injury

Question 6. Soldering.

Answer:

Soldering:

• It is the process of joining two metals together by adding the third metal
• The soldered metal should have a melting point equal to or lower than the two metals
• To increase the flow of solder, flux is added to it
• However, too much of flux leads to the flowing away of solder
• This is prevented by the addition of antiflux.

Question 7. Surface Hardness.

Answer:

Surface Hardness:

• It is the property that is used to predict the wear resistance of a material and its ability to abrade opposing dental structures
• Various hardness tests are used to determine the hardness of different dental materials
• They are
  • Brinell hardness test
  • Rockwell hardness test
  • Knoop hardness test

Question 8. Modulus of elasticity

Answer:

Modulus of elasticity:

Definition:

• It is the relative stiffness or rigidity of material within the elastic range

Measurement:

• It is the ratio of stress to strain and is described as E

Importance

• It indicates that the less the strain, the greater will be the stiffness
• Elastic modulus has a constant value
• It is not affected by the amount of plastic and elastic stress that is induced in the material
• It is independent of the ductility of the material
• The modulus of elasticity of enamel and dentin describes that
• Enamel is stiffer and more brittle
• Dentin is more flexible and tougher

Unit

• Giganewtons per square meter (GN/ m²)
• 2326 gauge needle is used to aspirate the contents of the lesion.

Question 9. Objectives of interim restorations.

Answer:

Objectives of interim restorations:

• Interim restorations are often required before the placement of a permanent restoration
• They are excepted to last for only a short period
• Zinc oxide eugenol is the cement of choice for it

Objectives:

• Arrests caries process
• Protects the teeth till they get permanently restored
• Allows pulp to heal

Question 10. Zsigmondy Palmer system

Answer:

Zsigmondy Palmer system:

• It was introduced by Adolph Zsigmondy of Vienna in 1861 for permanent dentition and modified for primary dentition in 1874.

For permanent dentition:

• As per this system, the oral cavity is divided into four quadrants and each permanent tooth has a specific number.
• Numbering progresses posteriorly from the midline.
• The central incisor was designated as 1 ending up with 8 for the third molar.

For primary dentition:

• The deciduous central incisors are designated A and progress posteriorly up to the 2nd deciduous molar alphabetically designated as E.