Orthograde root canal (normal)

Question 1

What is at the end of the root

Answer 1

Apical delta
5-20 foramina

Question 2

What angle are dentin tubules to pulp

Answer 2

90 degrees

Question 3

Contents of pulp

Answer 3

soft tissue connective tissue: odontoblasts, vascular, lymphatic and nervous tissues as well as odontoblasts, fibroblasts, fibrocytes, collagen fibers, elastic fibers, blood vessels and lymph and nerves

Question 4

Inflammation of the pulp

Answer 4

Pulpitis

Question 5

Used to remove pulp at 180 degree turn

Answer 5

Barbed broach

Question 6

Difference between k files and H files

Answer 6

K-Type, K-File
Twisted three or four sided tapered pyramid
K-files are more flexible then K-Reamers

Hedstrom files ( H Files)
Machine cute from a round metal blank or wire. Spiral groove on a tapered pointed instrument
Best in a push- pull technique, can engage into the dentin with a turn and pull technique

Question 7

Taper of endo instruments

Answer 7

0.02mm

Question 8

Forms of gutta percha

Answer 8

Crystalline Beta form is more rigid–stable at room temp, less flowable when heated

with heating it transforms to the Alpha form – brittle at room temp, flowable when heated

Question 9

Step back technique

Answer 9

Beginning with the smallest file just shy of apex and moving back while increasing file size
WL determined first

Question 10

Crown down technique

Answer 10

Beginning with the larger file to remove coronal debris and moving small as the file moves closer to apex

Question 11

Color order

Answer 11

White 15, yellow 20, blue 25, green 30, black 35

Question 12

Gates glidden

Answer 12

Used to enlarge coronal access

Question 13

Peeso reamer

Answer 13

Coronal flaring

Question 14

Bleach

Answer 14

NaOCL
Full stregnth between 5-6%
Most commonly used - antibacterial capacity and the ability to dissolve necrotic tissues
Strong base (pH 11), saponification occurs in organic materials, more effective at higher temperatures
Rarely allergic reaction, does react with chlorhexidines solution - creates a parachloroaniline - may be toxic

Question 15

Chlorhexadine

Answer 15

Used for general disinfection purposes and treatment of skin, eye and throat infections
pH between 5.5-7
Cationic nature - can stay in the dentin after rinsing the canal , gives a slow release potential
Does damage fibroblasts- cautious use in repeated areas
CHX with NaOCL precipitates and has a color change - worse at 2%
CHX with EDTA has a white precipitate - creates a salt - not chemical rxn

Question 16

EDTA

Answer 16

Ethylenediaminetetraacetic Acid (EDTA) usually 17%
Chelate and remove the mineralized portion of the smear layer

Question 17

RC prep

Answer 17

EDTA and urea peroxidase

Question 18

What are the 4 classes (starting at 0) of Endo-perio lesions

Answer 18

0- Primary endo
1- Endo-perio
2- Perio-endo
3 - True combination

Question 19

What are the four classes of ISO instruments

Answer 19

1- Hand files, pluggers, spreaders, broaches
2- 2 part. engine. driven = lentulo and mcspadden
3- 1 part engine = gates. glidden, peeso
4- filling points and paper. points

Question 20

2 types of gutta percha

Answer 20

1 - standard = correspond. to the size of of endo instuments
2- conventional = similar to endo spreaders.

Question 21

Types of sealers

Answer 21

Zinc oxide eugenol, Calcium hydroxide, non eugenol. (ZO, barium, bismuth), Glass ionomer, Resin (epoxy AH or Methacrylate endorez), silacone. (Guttaflow), Silicate (MTA)

Question 22

At D16 what is the size of taper

Answer 22

36mm (16x.02)

Question 23

MTAD

Answer 23

Doxy, citric acid, detergent

Question 24

Answer 24

Question 25

Near pulp exposure

Answer 25

.5mm of dentin left

Question 26

Tublules per mm

Answer 26

wiggs = 30-40000 Niemiec = 30-96000 1mm = 52000

Question 27

Bacteria of intact vs fractured teeth

Answer 27

In intact teeth, >90% of bacteria are obligate anaerobes, while teeth with pulp exposure harbor a population of almost 70% obligate anaerobes within their apical third.

Question 28

Hayflick limit

Answer 28

Somatic cells have a limited life span and capability for division,

Question 29

Relationship between luxation and pulp survival

Answer 29

concussion

Question 30

Storage of luxated teeth

Answer 30

Tap water – bad (hypotonic, rapid cell lysis) Hank’s balanced salt solution (HBSS), Save-a-Tooth – both effective saliva Low-fat milk also excellent for up to 6 hrs, esp if kept chilled (4⁰C) If milk used for >15 min, soak in HBBS for 30 min before replantation

Question 31

Time to reimplant avulsed tooth

Answer 31

60 min if dry and if solution immature teeth can be up to 3 hours

Question 32

Apexification vs Apexogenesis.

Answer 32

Apexification - calcium barrier in a nonvital tooth Apexogenesis - trying to maintain or stimulate vital tissue to maintain dvpt