7. Foundation Restorations for Vital Teeth II

Question 1

What are the different retention and resistance features of foundation restoratiosn

Answer 1

• Pins
• Parallelism of walls of the prep
• Proximal box form
• Retention grooves in proximal line angles
• Circumferential/partial grooves “slots”
• Amalgam Pins

Question 2

What are the three types of pins which ones do we use in clinic

Answer 2

• Cemented
• Friction-locked
• Self-threading**

Question 3

Which pin type has a pin hole diameter that is larger than the pin

Answer 3

cemented

Question 4

How are friction locked pins placed compared to self threading pins

Answer 4

Friction locked
-taped into place with a mallet

Self threading
-Placed by hand wrench or a contra angle hand piece

Question 5

Which pin type places the least internal stress on the tooth

Answer 5

cemented

Question 6

Which pins are the most and least retentive

Answer 6

Most= self-threading 
Least= Cemented

Question 7

What are the four sizes of self-threading pins and which one is the most commonly used

Answer 7

• Minuta
• Minikin*
• Minim**
• Regular

Question 8

About how much smaller is the pin hole diameter than the pin for self-threading pins

Answer 8

0.002 inches smaller

Question 9

What color are the minikin and the minim pins

Answer 9

red= minikin and gray= minim

Question 10

(Larger/smaller) diameter pins are more retentive

Answer 10

larger

Question 11

Compare the pin depth for minikin and minim pins

Answer 11

• minim= 2 mm

- minikin= 1.5 mm

Question 12

Optimum depth into dentin for pins is…

Answer 12

2.0-3.0mm (2mm)

Question 13

What are the benefits of a pin drill having a shoulder stop self-limiting feature

Answer 13

• Depth reference
• Reduces chance of perforation
• Prevents the tip of the pin from putting stress on the dentin

Question 14

What are the factors that need to be considered when deciding how many pins to place

Answer 14

• Size of the pin
• Amount of remaining tooth structure
• Other mechanical R/R features employed
• Anticipated occlusal forces on the final restoration

Question 15

T/F Pins strengthen the tooth

Answer 15

f

Question 16

1 pin should be used for per missing….

Answer 16

• cusp
• line angle
• proximal surface

Question 17

Incorporation of pins weakens composite or amalgam more

Answer 17

amalgam

Question 18

Do pins weaken alloy-reinforced GI

Answer 18

no

Question 19

Orienting the pins _ to the tensile stress is most favorable

Answer 19

parallel

Question 20

As the number of pins increases the fracture resistance of amalgam (increases/decreases)

Answer 20

decreases

Question 21

Acid treatment of the pin surface will enhance the bond to what and results in improvement of…

Answer 21

composite… with improvement in fracture resistance

Question 22

Which has greater retention resin or amalgam cores retained with pins

Answer 22

no difference

Question 23

What is the max number of pins you should use per tooth and why

Answer 23

3 because you do not achieve significantly improved R/R with more than 3 pins

Question 24

How much space should be placed between pins

Answer 24

• Depends on the size of the pin
• Minim= 5 mm
• Minikin= 3 mm

Question 25

pin placement should be _-_mm _ from the DEJ

Answer 25

0.5-1 mm pulpal

Question 26

If the pin is placed past the CEJ if should be placed at least _mm from the external root surface

Answer 26

1mm (allows space for the finishline)

Question 27

Where are the primary locations for pin placement and the unacceptable places

Answer 27

``` Primary= line angles Unacceptable= furcations and concavities (maxillary first PM has a mesial concavity) ```

Question 28

What must oppose each pin you place

Answer 28

another retentive feature (could just be a vertical wall)

Question 29

The pin is placed _-_ mm (outside/inside) the DEJ

Answer 29

0.5-1 mm inside

Question 30

The started hole is placed with the (fast/slow) speed handpeice with what bur

Answer 30

Slow with torque multiplier | -1/4 or a 1/2 round bur

Question 31

What is the name of the technique called to help you determine the angulation of the pin

Answer 31

Twist drill alignment- place the drill along the external surface of the tooth and use the angulation to place the pin

Question 32

How deep in the pin hole

Answer 32

2 mm

Question 33

The slow speed should be running in (forward/reverse) when the pin channel is made

Answer 33

forward

Question 34

What are the likely reasons why the drill may not be drilling

Answer 34

- Dull drill - Flutes obstructed with debris - Drill is running in reverse - Drilling in enamel rather than dentin

Question 35

How many torque reducers are needed on the slow speed to make the pin channel and for pin placements

Answer 35

Pin channel -Only one either the 10:1 latch or the torque multiplexer Pin placement -must use both

Question 36

What should you do if you placed your pin too close to a vertical wall in your prep and you can't fit an amalgam condersor in there

Answer 36

reduce the wall back with a bur

Question 37

If you need to reduce the height of a pin down with a bur how is the bur angled relative to the pin

Answer 37

bur is at a right angle to the pin

Question 38

The pin is bent toward where to reduce its height and prevent prepping it

Answer 38

toward the center of the prep

Question 39

Horizontal pins are used to

Answer 39

reinforce a lone-standing cusp

Question 40

Horizontal pins should be placed where relative to the occlusal DEJ

Answer 40

1 mm below the occlusal DEJ

Question 41

The most likely explanation(s) for a loose pin is

Answer 41

the channel prep was not precise or cutting the pin improperly

Question 42

If you have a loose pin what can you do

Answer 42

- Use a larger pin - Drill another channel (1.5 mm away) - Convert the loose channel into another retentive feature

Question 43

Cracks in the dentin can occur after pin placement as a result of what

Answer 43

the pin bottoms out in the channel

Question 44

How can you tell if you perforated

Answer 44

- Sudden drop in drill - Pain - Blood

Question 45

How can pulpal perforations be avoided

Answer 45

- Current X-ray and knowledge of pulp anatomy | - Avoid high risk areas

Question 46

With a pulp perforation with a pin what should you do for the following scenarios - Questionable pulp status - Indirect tx planned - Direct restoration

Answer 46

- Questionable pulp status = RCT - Indirect tx planned = RCT - Direct restoration = Direct pulp cap

Question 47

What should you do if you perforated into the gingival sulcus

Answer 47

- Cut the pin flush - Drop the finishline - Or condense amalgam internally and carve it externally

Question 48

What do you do if you perforate the periodontium with a pin past the epithelial attachement

Answer 48

- Crown lengthening to access the pin or perforation - Seal the perforation with .... - MTA externally - Adhesive and resin internally *Most complicated to handle

Question 49

What are the post op instructions for a person receiving a amalgam foundation restoration

Answer 49

- Tooth should remain generally comfortable - Avoid heavy chewing pressure for 24 hrs - "occlusal awareness" requires adjustment - Report any issues or concerns