Protecting the pulp

Question 1

What are we protecting the pulp from?

Answer 1

bacterial insult

thermal discomfort

chemical attack

Question 2

What can cause a chemical attack

Answer 2

• constitutes of certain resorative materials
• acids in certain dentine bonding agents
• residual acid from acidogenic bacteria

Question 3

What causes thermal discomfort?

Answer 3

• Heat released during polymerisation reaction when curing materials
• hot food/drink
• cavity preperation produces heat

Question 4

What happens to pulp in cavity preperation?

Answer 4

• Increase in inflammatory cell infiltrate
• preperation results in ‘smear layer’ left; which occludes the dentine tubules with:
• bacteria from cavity
• collagen
• Hydroxyapatite

Question 5

What is the ideal pulp protection?

Answer 5

non toxic

non irritant

bacteriostatic

gives good coronal seal

thermal/Electrical insulator

strength to withstand restoration placement e.g. condensing amalgam

radiopaque

compatible with wide range of restorative materials

Obtundant (soothing) effect on dental pulp

DENTINE IS THE IDEAL ONE!

Question 6

What materials are available to protect pulp?

Answer 6

Calcium hydroxide

Reinforced/resin-modified glass polyalkenoates (glass ionomers)

Question 7

What is calcium hydroxide?

what are its brand names?

Answer 7

brand names: Dycal, Unocal

• initially irrates pulp due to high pH- reactionary dentine laid down
• High pH means it is also bacteriocidal
• thermal/eletrical insulator
• radiopaque
• insufficient strength for condensation
• not adhesive- no doronal seal

Question 8

What is Glass polyalkenoates?

what is its brand name?

Answer 8

Brand name: Vitrebond

• Low pH- only mildly irritant to pulp
• contains fluoride- bacteriostatic
• thermal/eletrical insulator
• sufficent strenght to withstand condensation
• directly adhesive so good coronal seal
• good compatibility with other materials
• may be chemical cured or reinforced with ‘resin modification’

Question 9

what to use where and when?

Answer 9

• Cavities of 2mm or less - no lining required
• Cavities significantly deep - withing 0.5mm of pulp - hard setting CaOH
• do not need to cover with RMGIC unless restoring with amalgam

Question 10

Where to use linings?

Answer 10

• Pulpo-axial wall
• Occlusal floor

i.e areas directly overlying the pulp

do not place ever on gingival floor as pulp is not effected in these areas

Question 11

What are methods of protecting the pulp?

Answer 11

Indirect pulp cap

When cavity extended to within 0.5mm of pulp

Capping material is applied to deapest part of cavity

Restored as normal

Direct pulp cap

When an exposed pulp is covered by a capping material

Use hard setting calcium hydroxide

Only successful outcomes under certain conditions

Stepwise Excavation

Question 12

What is criteria for direct pulp capping?

what is the technique?

Answer 12

Criteria

• tooth is vital
• no pain history in tooth
• no perio history
• pulp pink and healthy and no excessive bleeding

Technique

• _​_micro-exposure dired with cotton wool! NO AIR DRYING!!!
• Pulp capping material applied to exposure, and other areas if close to pulp
• resotre tooth as normal

Question 13

What happens in Stwpwise Excavation?

Answer 13

• management of deep carious lesion to avoid pulp exposure and thus reduce the risk of pul[ pathoses
• partial caries removal employed
• caries overlying pulp left in situ
• cavity dressed and revisited later…

Pulp exposure avoided by allowing time for new dentine to be laid down and for lession to ARREST

Question 14

What is stepwise excavation technique?

Answer 14

1. ​ LA, access lesion and begin caries removal as normal
2. Clear ADJ/margins of all carious tooth tissue
3. Soft leahery wet caries on pulpal floor/pulpo-axial wall left alone
4. Dress the tooth with a material that gives a good coronal seal- GIC (pink useful)
5. Remove all of the dressing at least 12 months later and review the cavity.
6. Cavity floor should now be stained but no longer soft - now firm. LESION ARRESTED.
7. tooth can now be restored with a pernament material
8. if soft dentine still present - consider repeating stepwise procedure again. (good coronal seal)