Hall Crown

Question 1

Who is the Hall technique named after?

Answer 1

Dr Norna Hall

GDP in Scotland

Question 2

What material are the metal crowns made from?

Answer 2

Nickel Chromium

stainless steel

Question 3

What were the problems with using pre formed metal crowns in the conventional way?

Answer 3

Difficult to prepare the primary teeth
Needed LA
Poor compliance
Risk of damage to the developing first permanent molar when preparing the E

Question 4

What percentage did the pre-formed metal crowns account for restorations before the hall technique?

Answer 4

1%

Innes and Evans 2009

Question 5

What are the requirements for caries?

Answer 5

Time
Susceptible tooth surface
Plaque
Bacteria

Question 6

Which surfaces are most prone to caries?

Answer 6

Base of fissures

Just below contact points

Question 7

Why are the bases of fissures and contact points most susceptible to caries?

Answer 7

Provide a very sheltered surface where an ecological niche favours cariogenic plaque maturation

Question 8

Which bacteria within the biofilm are non-cariogenic?

Answer 8

Strep salivarius

Strep Oralis

Question 9

Which bacteria within the plaque biofilm are carogenic?

Answer 9

Strep Mutans

Lactobacilli

Question 10

Which acids are produced from the bacteria?

Answer 10

Lactic
Maleic
Proprionic

Question 11

Which acid produced as a by product of ferment able carbohydrates has the worse affect on enamel?

Answer 11

Lactic

biggest molecular value therfore takes the longest to diffuse out of the plaque

Question 12

What is the major, minor and pain failure rates for hall crown vs normal restorative material?

Major failure: abscess/irreversible pulpitis
Minor failure: Lost crown reversible pulpitis

Answer 12

Innes, Evans, Stirrups 2008
RCT that looked at 128 SSC and 128 conventional restprations

restoration vs Hall crown

Major failure: 15% vs 2%
Minor failure: 46% vs 5%
Pain: 11% vs 2%

Question 13

What are the potential problems arising from Hall crowns?

Answer 13

Time: 13% of hall crowns need orthodontic separators

Increase in OVD

Question 14

When should the recall time be after placing a SSC?

Answer 14

2 weeks to assess any problems with OVD/TMJ

Question 15

Under which circumstances are SSC not suitable?

Innes and Evans 2009

Answer 15

Signs of irreversible pulpitis or signs of irreversible pulpitis
non-physiological mobility
Insufficient sound tissue to retain the crown
patient at risk from bacterial endo
Patient co-op where the clinician cannot be sure the crown can be fitted without damaging the airway
parent or child unhappy
Self-cleansing arrested carious lesion

Question 16

When are hall crowns indicated?

Innes and Evans 2009

Answer 16

early to moderate class 2
active caries in D's and E's
can be used for class 1 cavities too where it is not possible to get a good peripheral seal

Question 17

What are the 6 stages to seating a hall crown?

Innes and Evans 2009

Answer 17

1. Sizing
2. Fill crown with cement
3. Locate and seat
4. Wipe excess cement away
5. Seat further (let the child bite down on a cotton wool)
6. Check and clean

Question 18

Why is it important to perform the second seating check?

Innes and Evans 2009

Answer 18

Because the crown can spring back a little and this can then cause some cement to be sucked back away from the gingival margin creating a breach in the seal

Question 19

How long should you wait between fitting SSC on opposing teeth?

Answer 19

minimum of three months to allow occlusal equilibration

Innes and Evans 2009

Question 20

What happens to the caries once the hall crown is placed?

Answer 20

caries progression slows or even arrests

Weerheijm 1992