Quiz 1 Flashcards
what are the two ways to move a file?
rotary and linear
what basic file types (hand, endohandle, or handpiece) use rotary movement?
hand and handpiece
what basic file types (hand, endohandle, or handpiece) use linear movement?
hand and endohandle
which filing motion is used for apical filing?
balanced force
which filing motion is good for oval shaped canals?
circumferential filing
list the 5 types of filing motions
- watch winding
- linear filing
- balanced force
- circumferential
- reaming
what is the degree of the flute angle on a K-type file?
40*
what is the degree of the flute angle on a hedstrom file?
60* (most positive rake angle)
what is the degree of the flute angle on a reamer file?
20* (most negative rake angle)
which file is the most efficient hand file and why?
hedstrom because it has the most positive rake angle, meaning it is the most efficient at shaving and cutting
what are the rake angle functions for negative, neutral, and positive rake angles?
- negative - smoothing
- neutral - smoothing, minimal cutting
- positive - cutting and shaving
what are the 3 elements of a file that influence cutting?
- sharpness
- rake angle
- force
file efficiency is reduced after how many strokes?
200
during coronal prep, what is the order that gates glidden drills are used?
4, #3, #2
what are the corresponding numbers and sizes associated with #4, #3, and #2 gates glidden drille?
#4 = 110 = 1.1mm #3 = 90 = 0.9mm #2 = 70 = 0.7mm
what is the ideal taper?
0.05mm
describe the step back technique used to achieve ideal taper
- start with the initial apical file (ex. #25)
- determine working length (ex. 18mm)
- set first three files to working length (#25, #30, and #35 all set to 18mm)
- set each additional file back 1mm (#40=17mm, #45=16mm, #50=15mm, #55=14mm, #60=13mm, etc)
- using the watch winding movement with 4-8 cycles per file, work your way up through the files using passive gentle touch pressure only, returning to the IAF between each successive file. irrigate between each file.
- repeat as necessary
what files have a triangular cross sectional shape?
flex R, large K-reamer, large K-file
what files have a square cross sectional shape?
small K-flex, small K-reamer, small K-file
what files have a diamond cross sectional shape?
large K-flex
what files have a teardrop cross sectional shape?
hedstrom
what files have a double helix cross sectional shape?
unifile, S-file
what do the stripes on a file shank designate?
size and taper
what does file color coding designate?
size, and it may vary according to the manufacturer
what does the file # designate?
diameter at D0
what are barbed broaches made of? what are they used for?
- stainless steel
- remove canal contents
what motions are used for root canal prep?
reaming and filing
do reamers have fewer or greater twists?
fewer twists, meaning they have increased flute spacing
what is the only motion that can be used with hedstrom files and why?
filing motion only (not reaming) because it can stress the file and lead to fracture