Old exam questions (mainly BDS2)

Question 1

Why has ditching occured in an amaglam resotration?

Answer 1

Material is repeatedly sressed for long periods at low stress levels below elastic limit
it may flow resulting in permanenet deformation
Amalgam sits proud of surface due to flow and is vunerable to fracture

Question 2

What can we do in a cavity prep to prevent diditching in amaglam

Answer 2

Remove all caries
Correct acid etch and bond
Use a lining material
Linging material helps spread force down the long axis of the tooth, instead of it placing stress on interface between tooth and resotration/

Question 3

Why does secondary caries form under resotrations?

Answer 3

Microleakage due to no chemical bond between resotration and tooth
Fracture of enamel at margins causing ditching has compromised any seal that was present at the restoration interface
Poor OH
No lining material underlying the amalgam meaning the dentine has no protection from bacteria

Question 4

How is cystic fibrosis passed down?

Answer 4

Inherited disroder

Question 5

How do you treat cystic fibrosis

Answer 5

Physio
Medication
Exercise

Question 6

How does cystic fibrosis affect the body

Answer 6

Inherited defect in cell Cl- channels
Produces excess sticky mucus
Lungs are congested
Pancreas - malabsorption of nutrients

Question 7

How do you test for cystic fibrosis

Answer 7

Perinatal testing

Sweat testing - measures salt content of sweat, which is higher in CF patients

Question 8

3 reasons why a bond to dentine may fail?

Answer 8

Over etch - collagen fibres collapse therefore the resin cannot penetrate
Over etch - too deep an aetch and the primer cannot penetrate the full depth of etch
Too dry - dentine surface collapses

Question 9

Define bioavailability

Answer 9

Fraction of adminstered dose of unchanged drug thart reaches systemic circulation and is available from clinical effect

Question 10

What is the definition of flowable composite

Answer 10

Lower filler content therefore less viscous than conventional composite
Used for filling pits, small fractures and luting agent
Higher polymerisation shrinkage
Lower fracture strength
Place with fibre ribbons

Question 11

What does light curing do?

Answer 11

Extended working time
Less finishing
Less waste
Less porosity

Question 12

What are some problems with flowable composite

Answer 12

Reduced mechanical properties
Lower variety of shades
More difficult to scuplt due to decreased viscosity
Discolouration over time

Question 13

What is polymerisation shrinkage

Answer 13

Depnedent on filler particle volume
Affects bond to tooth - stresses develop at hard tissue
Potential from cuspal fracture and microleakage

Question 14

6 links of chanin of infection

Answer 14

Infectious agent
Reservoir
Portal of exit
mode of transmission
Portal of entry
Susceptible host

Question 15

7 modes of transmission

Answer 15

Direct
Indirect
Inhalation
Ingestion
Inoculation
Intercourse
Mother to infant

Question 16

What should you do in the event of a sharps injury

Answer 16

Stop what you are doing
Run the injury under warm water and squeeze the area to encourage bleeding
Wash throughly with soap and water but do no scrub
Cover site with waterproof dressing
Complete incident report form and report to occupational health

Question 17

What are advantages of the hall technique

Answer 17

Allows pre formed metal crown to be placed over carious primary molars
Non invasice and quick
Requires no LA and no tooth prep
Requires patient compliance and trust in operator ability

Question 18

Indications for hall technique

Answer 18

No radiographical sign of pulpal involvement

Sufficient amount of sound tooth tissue

Question 19

What is the pterygomandibular raphe

Answer 19

Ligamentous fibrous band attached to the hamulus of the medial pterygoid muscle and the mylohyoid

Question 20

Where is the pterygoidmandibualr raphe situated and how is it recognised in the paitents mouth

Answer 20

Posteriorly to the last standing tooth

Recognised by palpating the anterior notch with thumb

Question 21

Where does the pterygomandibular space lie?

Answer 21

Between the ramus of mandible and the medial pterygoid muscle