class II composite restoration

Question 1

why are composites being used more

Answer 1

alleged health concerns with amalgam
environmental concerns
demands for use of adhesive material with less invasive cavity prep
patient demand for aesthetics

Question 2

cavity indications for composite use

Answer 2

small carious lesions that allow conservative pre

• restorations that consider aesthetics
• moderate sized class II
• where patient is allergic to metal
• wehre unsupported enamel may be streghtened
• not possible to obtain retention from non adhesive restoration

Question 3

contradictions for composite use

Answer 3

patients with high caries activity 
poor OH
where isolation not possible
multiple large restorations with cuspal contacts
patient with bruxism
allergies
cavity margins extending beyond enamel
time constraints

Question 4

patients iwht high caries activity

Answer 4

risk of recurrent cares high, 
best placing GIC/temporary ,
- less technique sensitive
- quicker
- easier to place
and have fluoride releasingproperties

Question 5

shade selection

Answer 5

taken before isolation with natural light

lighter shades cure more readily

Question 6

cavity prepraton

Answer 6

remove disease only
removal of any previous restorations
bond strengths greater for enamel than dentine
attempt to preserve enamel at cavity margins and gingivlafloor

Question 7

proximal box

Answer 7

extended just pas the contact point to allow marginal caries removal

• aids matrix placement-
• vertical box margins may be left in contact if this does not compromise matrix placment

Question 8

when are bevels not recommended

Answer 8

occlusally
may result in a thin margin of composite which could be prone to fracture under occlusal load
gingival margins
- could lead to loss of cervial enamel, want to keep as much of the gingival floor for bonding

Question 9

advantage of proximal bevel

Answer 9

optimise mariganal seal

increases SA for bonding at cavity margin

Question 10

what can be used if matrices are tights

Answer 10

orthodontic separators 3-7 days before

pre wedging the tooth

Question 11

what do sectional matrices repalce

Answer 11

one wall

Question 12

how should you place composite

Answer 12

small increments
- reduce polymerisation shrinkage
- decreases internal stress (C factor)
oblique layering technique

Question 13

what is shrinkage

Answer 13

composite pulling away from the margins of the cavtity
can lead to micro leakage and recurrent caires
- creates forces on the tooth as it pulls inwards (internal stress)

Question 14

C factor

Answer 14

ratio bonded: unbonded surfaces of caivity 
e.g. class 1, 5 bonded : 1 unbonded=5 so greater internal stress than class 2

Question 15

Bulk fill composites

Answer 15

allow high filler composites to be placed using a sonic device

• changes compsoite viscosity to allow flow
• increase polymerisation
• low polymerisation shrinkage
• better aesthetics
• better seal

Question 16

light curing

Answer 16

light tip should be close to RB within 3mm

lighter shades cure more readily than darker

Question 17

what can be used for finishing and polishing

Answer 17

discs/cups
impregnanted rubber points
aluminium oxide pastes
surface glazes
microfine diamond bur