Cavity prep

Question 1

Clinical benefits of pin tweezers

Answer 1

secure placement and removal of components
handy ball burnisher
naturally closed position minimises risk of dropping componenets

Question 2

Clincal beenfits of rings

Answer 2

Spring strength and meomry facilitates strong proximal contacts
the rings clasp around wedge so possible to insert wedge after placement of ring

Question 3

Clinical benefits of sectinoal matrix band

Answer 3

easy placement and removal
accurate contacts and tight marginal seal
minimised flash and finshing

Question 4

Wedges

Answer 4

adapt the matrix band to the cervial margins of a cavity to avoid excess of filling material
provides temp tooth seperation 
prevents excess amalgam gingivally
aids proximal wall contour
prevents movement of matrix band

Question 5

Reasons for lining placement

Answer 5

protection of pulp
secondary caries
enamel contamination 
risk of microleakage occurs 
effect on bonding

Question 6

Final seal of restoration

Answer 6

smooth margins
apporpraite cavo-surface margin angle
no unsupported tooth tissue
no stress concentrators
internal anatomy that allows adapation of material