Anatomy...Acess...Canal Prep

Question 1

What should you think of when you think Anatomy?

Answer 1

• Think 3-D!
• Expectations
• Variations
• Coronal, chamer, canal, apical

Question 2

What does the Law of Centrality state?

Answer 2

Pulpal floor always located in center of tooth at level of CEJ

Question 3

What does the law of the CEJ state?

Answer 3

The CEJ is the most consistent, repeatable landmark for locating the position of pulp chamber

Question 4

What does the law of Concentricity State?

Answer 4

The walls of the pulp chamber are always concentric to external surface of the tooth at level of the CEJ

Question 5

What does the first law of symmetry state?

Answer 5

Except for max molars, orifices are equidistant from a line draw in a MD direction through the pulpal floor

Question 6

What does the second law of symmetry state?

Answer 6

Except for max molars; Orifices lie on a line perpendicular to a line drawn in MD direction across center of pulpal floor

Question 7

What is the Law of color change?

Answer 7

The color of the pulp chamber floor is always darker than walls

Question 8

What are the 3 laws of Orifice Location?

Answer 8

1. The orifices are always located at junction of walls and floor
2. The orifices are located at angles of floor-wall junction
3. The orifices are located at terminus of root developmental fusion lines

Question 9

Describe the 4 Weine Classifications…

Answer 9

Question 10

How many canals does a Maxillary Anterio typically have?

Answer 10

Question 11

How many canals does a Mandibular Anterior Tooth typically have?

Answer 11

Question 12

What % do Mandibular Canines have 2 canals?

Answer 12

22%

Question 13

How many canals does a Maxillary Premolar typically have?

Answer 13

Question 14

Which pre-molar is the 50/50 tooth?

Answer 14

Max 2nd Premolar

Question 15

How many canals does a Mandiblar Premolar typically have?

Answer 15

Question 16

Which pre-molar has a 97% chance of having 1 canal?

Answer 16

Mandibular 2nd Premolar

Question 17

How many canals does a Maxillary 1st Molar typically have?

Answer 17

Question 18

What is the % chance there will be MB2 in Max 1st Vs Max 2nd Molars?

Answer 18

• 1st Molar: 1 canal 20%, 2 canals 77%, 3 canals 3%
• 2nd Molar: 1 canal 63%, 2 canals, 37%

Question 19

How many canals does a Mandiblar Molar have typically?

Answer 19

Question 20

Which tooth is likely to have a “C” shaped canal?

Answer 20

Mandibular 2nd Molar, 3%

Question 21

Describe Straight-Line Access…

Answer 21

• Improves vision
• Reduces curvature
• Facilitates instrumentation & Obturation
• Immproves instrument control

Fewer misadventures

Question 22

Why might it be wise to access without a RD?

Answer 22

• Ensure correct toth
• Visulize long axis - facilitate correct approach

Question 23

How do you arrive at an appropriate working length?

Answer 23

• Estimate
• Radiogaph (0.5 - 1.0 mm)
• Tactile sense
• Electronic Apex Locator
• Paper Point
• Patient Sensation

Question 24

What is the average surface to constriction?

What is the aerage deviation major to apex?

Answer 24

• Avg to constriction 0.75
• Avg deviation major to apex 0.59

Question 25

Describe this picture...

Answer 25

Major foramen is larger than minor formaen at constriction - looking from the external root surface apex

Question 26

Describe how a Root ZX works?

Answer 26

* "Ratio method" * Simultaneously measures impedance of two different frequencies, calculates the quotient of the impedances, and expresses this quotient as a position of the file inside the root canal * No calibration required * Small files and large files yield similar readings * Rootz ZX identifies narrowest canal diameter even wen an anatomic apical constriciton did not exist of was destoryed by instrumentation

Question 27

What are the objectives of Cleaning & Shaping?

Answer 27

* Total removal of content of pulp space (tissue, debris, bacteria, byproducts) * Develop straight line access to apical region * Maintain central axis of canal * Keep apical constriction small and in original position * Continuously tapering, smooth, funnel-shaped preparation

Question 28

What type of hand file is this?

Answer 28

* Flex R * K-Reamer (large) * K-File (large)

Question 29

What type of hand file is this?

Answer 29

* K-Flex (small) * K-Reamer (small) * K-File (small)

Question 30

What type of Hand File is this?

Answer 30

* K-Flex (large)

Question 31

What type of hand file is this?

Answer 31

Hedstrom

Question 32

What type of hand file is this?

Answer 32

* Unifile * S-File

Question 33

What is the Material/Cross-Section/Tip Design of K-File? Hand File...

Answer 33

* Material: SS * Cross - Section: Triangular/Square * Tip Design: Cut

Question 34

What is the Material/Cross-Section/Tipe design of the hand file K flex?

Answer 34

* Material: SS * Cross - Section: Rhomboid * Tip Design: Cut

Question 35

What is the Material/Cross-Section/Tip Desing of Hand File Flex-R?

Answer 35

* Material: SS * Cross-Section: Triangular * Tip Design: Safe

Question 36

What is the Material/Cross-Section/Tip Design for Sureflex Hand Files?

Answer 36

* Material: NiTi * Cross Section: Square * Tip Design: Safe

Question 37

Describe the Increase in Diamter in this .02 tapered file?

Answer 37

0.32 mm Increase in Diameter from DO to D16

Question 38

Describe the Increase Diameter in the .04 tapered file below...

Answer 38

0.64 mm Increase in Diamter from DO to D16

Question 39

What is Rake Angle?

Answer 39

Question 40

What are the 2 types of Rake Angles?

Answer 40

* Negative Rake * Positive Rake

Question 41

What is the difference between a Scapre and Cut Rake Angle?

Answer 41

In the middle of these is planning with the blade faced down...

Question 42

Describe the Rake on this K3 Niti File that you use...

Answer 42

* K3: Assymetric flutes separated by lands. * Positive rake angle * More resistant to fracture

Question 43

What are some Advantages of a NiTi Rotary Instrumentation System?

Answer 43

* Speed * Less fatigue * Costly * Learning Curve * Design pulls debris out * Flexible * Less transportation * Fracture resistant

Question 44

What are 2 instruments for shaping orifices?

Answer 44

* Gates Glidden: Drills Sizes 1-6 * Peeso Reamers: Sizes 1-6

Question 45

Why use Chemical Disinfection if you are instrumenting the canal system?

Answer 45

* All aspects of a canal system cannot be reached by files * Need some method to further clean these spaces

Question 46

Describe 8% (Full Strength) NaOCl...

Answer 46

* Gold Standard * Dissolves necrotic tissue * _Removes the organic portion of smear layer_ * Germicide * Detoxifies Endotoxins * Lubricant * Bleaching Agent * Deordorizer \*Dilution reduces all beneficial effects!

Question 47

What will 2% Chlorhexidine Gluconate not do?

Answer 47

Dissolve Tisue! ## Footnote \* Alternative endodontic irrigant for sodium hypochlorite allergic patients

Question 48

What is the % associated with EDTA?

Answer 48

17%

Question 49

Describe some attributes of 17% EDTA...

Answer 49

* Chelating agent * Lubricant * Help remove inorganic portion of smear layer * Ethylenediaminetetracetic Acid

Question 50

What is this?

Answer 50

Smear Layer

Question 51

Answer 51

Question 52

What type of needle is ideal for delivering Intracanal Irrigation?

Answer 52

Question 53

What are some characteristics of Calcium Hydroxide?

Answer 53

* High pH...Alters Environment * Antimicrobial * Dissolves tissue * Favors calcification (alkaline phosphatase formation) * Favros osteogenesis * Causes limited tissue necrosis...elicits healing response * Helps dry "weeping" canals * Halts or slow resorptive processes * Effective for 1 week

Question 54

Describe how Alkaline Phosphatase leads to dentin bridge formation?

Answer 54