cr stuff

Question 1

ways to overcome polymerisation shrinkage

Answer 1

• incremental placement of CR of 2mm, to reduce amount of setting contraction each time
• CR should be placed in a sloped manner to reduce the number of bonded surfaces to reduce contraction stresses on adhesive bond
• for deep cavities, the bulk of CR may be reduced by placing a base below it

Question 2

what is nanoleakage

Answer 2

occurs when resin tags do not totally infiltrate the entire depth of etching

Question 3

downside of one step self etch adhesives compared to two step

Answer 3

one step self etch have higher water absorption/ solubility,mechanical properties may be significantly compromised in the presence of more water

something about how

water is needed to ionize acidic methacrylate monomers but compromise must be made to ensure that ater dont lower monomer conc to levels that jeopardizes the bonding efficacy