Cavity Liners

Question 1

What is biodentine?

Answer 1

A new bioactive cement with dentine-like mechanical properties which can be used as dentine substitute on crowns and roots

Question 2

What is the base of biodentine?

Answer 2

Calcium-silicate

Question 3

What makes biodentine radiopaque?

Answer 3

Zirconium Oxide

Question 4

Name 5 coronal clinical indications of biodentine

Answer 4

1. Temporary enamel restoration
2. Deep or large carious lesions
3. Deep cervical or radicular lesions
4. Pulp capping
5. Pulpotomy

Question 5

Name 4 root clinical indications for biodentine

Answer 5

1. Root furcations / perforations
2. Internal / external resorption
3. Apexification
4. Retrograde surgical filling

Question 6

Why is biodentine used as a direct pulp cap?

Answer 6

• Calcium hydroxide has been standard for years
• Exhibits poor bonding to dentine and shows overtime material resorption
• Biodentine stimulates tertiary dentine with tighter marginal seal

Question 7

Describe how direct pulp capping is carried out

Answer 7

• Once pulp exposed bleeding must be controlled within 5 minutes
• Cavity cleaned with 5% sodium hypochlorite on cotton wool pledget
• Biodentine placed directly over exposed pulp tissue
• Cavity filled to occlusal level with biodentine
• After 12 mins occlusion checked and adjusted
• 3 months later partial removal of biodentine to cap restoration with composite

Question 8

Name 2 uses of calcium hydroxide

Answer 8

1. Cavity liner (not any more)

2. Pulp capping

Question 9

Describe the method of use of calcium hydroxide

Answer 9

• Base and catalyst mixed together on paper pad
• Mixing time 10s
• Working time 2m20s
• Setting time 2m30s to 3m30s

Question 10

Describe 4 properties of calcium hydroxide

Answer 10

1. Low compressive strength
2. High solubility
3. Radiopaque
4. Hard setting

Question 11

Describe 4 advantages of calcium hydroxide

Answer 11

1. Does not inhibit setting of acrylic or composite
2. No negative effect on aesthetic result
3. Stimulate formation of secondary dentine
4. Aids restoration of pulp vitality

Question 12

Describe 3 disadvantages of calcium hydroxide

Answer 12

1. Mechanically weak when pressure is applied
2. Soluble over time
3. Does not form tight seal with dentine so needs layer of RMGI placed to complete seal

Question 13

What are cavity liners?

Answer 13

Thin layer of material placed at deepest portion of the cavity, providing pulpal protection or dentinal regeneration

Question 14

Describe Calcimol LC

Answer 14

• Light cured, resin modified calcium ion releasing base liner and pulp capping material
• Applied to dentine at maximum 1mm

Question 15

Name 2 indications for Calcimol LC

Answer 15

1. Indirect pulp capping

2. Lining under deep amalgam restorations

Question 16

Name 3 types of insulation provided by liners under deep amalgam restorations

Answer 16

1. Electrical
2. Thermal
3. Chemical

Question 17

Name 6 advantages of Calcimol LC

Answer 17

1. Calcium ion release promotes hydroxyapatite and tertiary dentine growth
2. High pH level has antibacterial effect
3. Flow on demand
4. High compressive strength
5. Raidopaque
6. Low solubility

Question 18

Describe how to select the correct Pro Matrix band

Answer 18

• Decide what size of band to use (4.5mm for premolars and 6mm for molars)
• Straight bands suitable for amalgam
• Curved bands suitable for composite
• Adjust toggle so it is positioned closest to gumline