Cusp Build-up and Pin Placement

Question 1

The mandibular molar has ___ buccal cusps, ____lingual cusps, ___ buccal groove(s), and ___ lingual groove(s) that extend from the occlusal surface.

Answer 1

3 B cusps
2 L cusps
2 B grooves
1 L groove

Question 2

How many fossae are in the mandibular molar?

Answer 2

3 (mesial, central, distal)

*mesial and distal are triangular grooves

Question 3

Mandibular 1st Molars:
The four _____ridges (of mesiobuccal/mesiolingual cusps, and of distobuccal/distolingual cusps) join to form two ______ ridges.

Answer 3

triangular

transverse

Question 4

True or False: When viewed from the buccal, the 3 buccal cusps of mandibular molars are all close to the same height.

Answer 4

True

However, remember that the distal cusp is narrower mesiodistally

Question 5

Name the three buccal cusps of mandibular molars.

Answer 5

mesiobuccal, distobuccal, and distal

Question 6

Placement of a class II amalagam, with the cusp build-up on most of the buccal surface, involves placement with a ________ Toffelmire retainer and an extended-width matrix band.

Answer 6

contra-angle

Question 7

How is the condensing technique modified when doing a cusp build-up?

Answer 7

“overfill condensing” must be used to account for height of missing cusp

Question 8

Why would a dentist place a pin?

Answer 8

to HELP RETAIN amalgam when one or more cusps have been lost

Question 9

Pin holes are drilled entirely within _____ and generally extend _____ deep, with _____ of the pin exposed within the preparation.

Answer 9

dentin
2 mm deep
2 mm exposed

Question 10

How many pins are placed per cusp?

Answer 10

one

Question 11

How many pin types are there? What are the types?

Answer 11

three

1. Threaded/Screw Type (hole smaller than pin size)-screw
2. Cemented (hole larger than pin size)-cement
3. Friction Lock (hole smaller than pin size)-tap it in

Question 12

What is the “general rule” for rubber dam isolation of posterior teeth?

Answer 12

punch holes for ONE tooth behind and TWO teeth in front

Question 13

True or False: During a cusp build-up procedure, a dentin protector is recommended.

Answer 13

True (ex. copal varnish)

Question 14

Why can’t a “universal retainer” be used for an MODBA preparation/build-up?

Answer 14

tooth structure must be re-built on the buccal, the part of the band that enters into the retainer slots will not adapt well to the buccal aspect of the tooth

Question 15

During placement of the matrix band and wedge, the band must extend ______ occlusal to the future marginal ridge and _____ gingival to the gingival margin.

Answer 15

0. 5 - 1.5 mm occlusal

0. 5 -1.0 mm gingival

Question 16

True or False: The marginal ridge should be convex from buccal to lingual.

Answer 16

False, CONCAVE

Question 17

True or False: Base should not be placed on enamel.

Answer 17

True

Question 18

If extension of the preparation (from a primary groove toward the cusp tip) is ______ to _____ the distance, consider capping the cusp.

Answer 18

1/2 to 2/3

>2/3 usually cap

Question 19

Complex amalgam restorations can be used as ____, ____, or ______ restorations.

Answer 19

1. Definitive (patient couldn’t afford a crown)
2. Foundation (RUC)
3. Control (pulp, perio, or caries issues)

Question 20

Why would amalgam be used as a “control restoration?”

Answer 20

• Pulpal Questions
• Periodontal Questions
• Acute Caries Present
• Severe Caries Present

*Control other issues before placing definitive crowns!

Question 21

We use the TMS pin system. What does TMS stand for?

Answer 21

thread mate system

Question 22

What is the drill diameter and pin diameter of the “Regular TMS” pin system? All other pins in this system are ______diameter.

Answer 22

Regular:
Pin = 0.78mm
Drill = 0.68mm

Other pins are of smaller diameter
(minim 0.61, minikin 0.48, minuta 0.38)

Question 23

Pins used at OSU are made of _____ alloy

Answer 23

titanium

Question 24

What is the pin characteristic that allows pins to snap off after drilling into the tooth?

Answer 24

“Self Shearing” Pin (small area that is NOT threaded)

Question 25

The pin drill is ____-shaped and is ____-limited

Answer 25

pear

depth

Question 26

Make sure the latch-head handpiece is set in the ____direction when using the pin system.

Answer 26

forward

Question 27

True or False: Pins should be placed at line angles and 2 drill widths in from the DEJ.

Answer 27

True

Question 28

How deep is a retentive well? How far into the tooth from the DEJ?

Answer 28

1. 5 mm deep from pulpal floor

0. 5 mm in from DEJ

Question 29

What is the “2-2-2-2 Rule?”

Answer 29

2 mm pin hole depth
2 drill diameters inside the DEJ
2 mm length of pin
2 mm amalgam over the pin

Question 30

If close to the pulp, _____ can be used as an indirect pulp cap to stimulate dentin.

Answer 30

calcium hydroxide (or RMGI)

Question 31

True or False: ZOE should not be used under composite.

Answer 31

True

Question 32

What is the purpose for using copal varnish?

Answer 32

seal tubules and prevent sensitivity