Composite And Amalgam 2 Flashcards
What is the chemically active component of composite
Monomer phase it polymerises to give a glassy polymer in the set state
Which layer of the tooth does bond better bond to
Bonds better to enamel than dentine
What are 6 effects of polymerisation shrinkage
Marginal staining
Microleakage
Secondary caries
Enamel micro cracks
Post operative sensitivity
Debonding
What is polymerisation contraction
If no adhesive is used leads to gap formation loss of marginal integrity leads to mircoleakage and failure
What is polymerisation stress
If adhesive is used composite tries to contract stresses develop and strain is placed on the bond
What is the configuration factor (C factor)
Num of bonded surfaces/Num of unbonded (free surfaces)
For layering in increments for composite what is the layering thickness
1mm - 1.5mm
MAX 2mm
What does classical incremental layering of composite provided
Preserves O2 inhibition layer
No water contamination once you started with filling
What does the modified incremental layering of composite reduce
The number of bonded surfaces per layer
What are 7 indications for use of amalgam
Large class II restorations
Class II restorations with open contacts
Deep subgingival restorations
Restorations where isolation is difficult
Heavy occlusal contacts
Core build up
Abutment teeth for partial dentures
What are 7 contraindications for amalgam
Class I restorations
Aesthetics
Primary dentition
Pregnant and breastfeeding women
Impaired renal clearance
Allergy
Children under 15
What does the BDHS and BDA say about dental amalgam
Does not consider the use of dental amalgam containing mercury a significant health risk
Is dental amalgam safe
There is no difference in general health of the dental personnel and general population
Where does mercury for dental amalgam come from
50% from natural source e.g. rock erosion, volcanoes
50% from human activities
What are the 6 waste management steps for amalgam
Install
Separate
Collect
Recycle
Clean
Return
