Seminar 4: Mechanical Prep

Question 1

What are the risks of apical prep before coronal prep?

Answer 1

Don’t know where the file is binding

Question 2

What are the benefits of coronal prep first?

Answer 2

Less likely to extrude
Working length changes less
Better idea of what is happening in the canal as the coronal aspect is loose and not binding

Question 3

What is the benefit of using shorter files over longer files

Answer 3

Better tactile feedback
Greater ability to transfer forces from your had to the file tip

Question 4

When determining apical prep size what should you consider ?

Answer 4

Taper: 5% taper then need ISO 30
Thin roots
Acute curvatures
Resorption ?

Question 5

Historically how was apical size determined and what problems did this pose ?

Answer 5

Weine suggested 3 sizes larger than first binding file
Too arbitrary
Too much root dentine removed

Question 6

What two methods of hand instrumentation are there?

Answer 6

Rotational
Push pull / Filing

Question 7

What is an example of rotational filing?

Answer 7

Stem winding

Balanced force

Question 8

What is an example of filing?

Answer 8

Anticurvature

Question 9

How are the threads aligned for instruments designed for rotational movements ?

Answer 9

Almost Parallel to long axis

Question 10

How are the threads aligned for instruments designed for filing movements ?

Answer 10

Perpendicular to long axis

Question 11

What cross section does a K FLex file have ?

Answer 11

Rhomboid

Question 12

What are the advantages of NiTI over SS files ?

Answer 12

Easier to create an Evenly tapered canal achieved
Fewer instruments required
Time efficient

Question 13

What are the disadvantages of NiTI over SS files ?

Answer 13

Expense
Can dull quicker than SS
Can fracture with no signs of damage