#5

Question 1

Spangberg and Langeland, ,1973

Answer 1

Biologic effects of dental materials
Toxicity of root canal filling materials on Hela cells in vitro
All materials are highly toxic when freshly prepared.
Kerr was less toxic than all others.
Chloropercha had the lowest toxic effect of all set materials.

Question 2

Stanley and Lundy, 1972

Answer 2

Dycal therapy for pulp exposures.

Dentinal bridge forms in direct contact with Dycal in 23 days. Necrotic pulp is removed and replaced

Question 3

Peciuliene, 2001, IEJ

Answer 3

Isolation of yeasts and enteric bacteria in root-filled teeth with chronic apical periodontitis.
IKI showed improved reduction in cultural microbes.
E. faecalis was a frequent isolate and showed resistance to traditional methods.

Question 4

Torabinejad, 2002, OOO

Answer 4

Clinical implications of the smear layer in endodontics: A review.
Bacteria can penetrate into tubules up to 150 microns.
10 fold if SL is removed.
Current evidence supports the removal of SL after instrumentation.

Question 5

Sen, 1995

Answer 5

The smear layer a phenomenon in RCT.

SL may slow y disintegrate around filling material or removed by bacterial by-products.

Question 6

Ørstavik & Haapasalo 1990

Answer 6

Smear layer cannot serve as a strict barrier to bacteria. It only DELAYS the bacteria penetration

Question 7

Yamada, 1983

Answer 7

Organic acids (e.g. Citric acid) are not as effective as chelating agents (e.g. EDTA) for the removal of smear layer

Question 8

Thompson, 2000, IEJ

Answer 8

Overview of NITI alloys
Austenite at high temps or low press
Martensite at low temps or high press

Question 9

Shuping, 2000,

Answer 9

Reduction of Intracanal Bacteria Using Nickel-Titanium Rotary Instrumentation and Various Medications.
Significant reduction in bacterial load seen after S3, showing that NaOCl requires a certain size of canal to become beneficial.
One week of CaOH significantly increases the number of negative cultures.

Question 10

Goerig, 1983, JOE

Answer 10

The instrumentation of root canals in molar using step-down technique.
Allows instruments to enter w/o interference
flaring, eliminates dental irregularities and pulpal tissue.
Straight access

Question 11

Sarkar, 2005, JOE

Answer 11

Physicochemical basis of the biologic properties of MTA
MTA is not an inert material, it is bioactive.
MTA releases all of its major cationic components, triggering the precipitation of HA on its surface.

Question 12

Chemical composition of MTA

Answer 12

Portland cement: 75%
Bismuth Oxide: 20%
Gypsum; 5%

Question 13

Love, 2001, IEJ

Answer 13

E. faecalis - a mechanism for its role in endodontic failure.
E. faecalis cells remain viable, and maintain the capability to invade dentinal tubules and adhere to collagen in the presence of human serum.
Invasion of dentin by bacteria was associated with cell adherence to type 1 collagen.

Question 14

Siren, Haapasalo, 1997

Answer 14

Microbiological findings and clinical treatment procedures in endodontic cases selected for microbiological investigation.
Enterococcus faecalis was seen more probably in cases with several treatment visits, failed root canal treatment, failed or open temporary restorations, and in form of monoinfection.

Question 15

Griffee, 1980

Answer 15

The relationship of Bacteroides melaninogenicus to symptoms associated with pulpal necrosis

Question 16

Brannstrom, 1986, JOE

Answer 16

The Hydrodynamic Theory of Dentinal Pain: Sensation in Preparations, Caries, and the Dentinal Crack Syndrome
Drilling and probing can also produced an outward displacement of fluid in the tubules.
Heat applied to intact dentine activates the c fibers

Question 17

Madison, 1988

Answer 17

An evaluation of coronal micro leakage in RCTT.

Not a good experiment.

Question 18

Senia, 1971

Answer 18

the solvent action of NaOCl on pulp tissue of extracted teeth.
surface contact, volume and exchange of solution may limit the effectiveness of NaOCl as a tissue solvent.
No difference between 15-30 min

Question 19

Safavi, 1990

Answer 19

Root canal dentinal tubule disinfection.

Use IKI for infected cases, flood canal for a few minutes.

Question 20

Goldman, 1989

Answer 20

The usefulness of dye-penetration studies reexamined.
trapped air must be taken into account when doing ink penetration studies.
Traped air affects the penetration of ink

Question 21

White and Hays, 1997

Answer 21

Residual Antimicrobial Activity After Canal Irrigation with Chlorhexidine.
On initial exposure chlorhexidine is at least as effective as sodium hypochlorite
CHC has substantive activity

Question 22

Thompson and Dummer, 1997

Answer 22

Shaping ability of ProFile.04 Taper Series 29 rotary nickel-titanium instruments in simulated root canals
ProFile .04 taper series 29 rotary instruments prepared simulated canals rapidly, without creating blockage, only limited loss of length and with good taper and flow

Pre op canal shape didn’t affect any of the parameters investigated

Question 23

Foreman and Barnes, 1999, IEJ

Answer 23

A review of CaOH.

calcium ions in the repair tissue does not come from the CaOH but prom the dental pulp.

Question 24

Pisanti and Sciaky, 1964

Answer 24

calcium ions present in the applied calcium hydroxide do not become incorporated in the mineralized repair tissue which derives its mineral content solely from the dental pulp.
CaOH is an initiator rather than a substrate.

Question 25

Pashley, 1990

Answer 25

Clinical considerations of micro leakage.

Question 26

Mader, 1984, JOE

Answer 26

Scanning electron microscopic investigation of the smeared layer on root canal walls