Cleaning and Shaping II

cleaning and shaping is what type of preparation?

chemo-mechanical

syringes: must use _______ lock attachment to prevent NaOCl accidents

Luer

needles: must reach ____-____ mm from WL or at least in apical 1/3 to be effective

1-2 mm

minimal #______ required for the irrigant to reach WL

#30

irrigation methods that create positive pressure (3)

1. syringe-needle

2. sonic device

3. ultrasonic cleaning

irrigation methods that create negative pressure (2)

1. endovac

2. wide spectrum sound energy

wide spectrum sound energy creates negative pressure = -______ & -_______ mmHg

- 13.07 mmHg

-17.19 mmHg

wide spectrum sound energy uses what solutions (2)

1. 2% NaOCl

2. 8% EDTA

commonly used endo irrigants (3)

1. NaOCl

2. chlorhexidine

3. EDTA

what components of NaOCl make it bactericidal? (3)

1. pH

2. chlorine ion

3. hypoclorous acid

what component of NaOCl makes it tissue dissolving?

chlorine ion

tissue dissolving: chlorine ion

_________ tissue >> _________ tissue

necrotic

vital

NaOCl advantages (3)

1. antimicrobial

2. tissue dissolving

3. inexpensive

NaOCl mode of action:

NaOCl has ______ pH ( >____)

high

> 11

NaOCl mode of action:

neutralization of _______ by NaOH →

AA

water & salt

NaOCl mode of action:

_____________ acid formation (oxidizer) → AA degradation & hydrolysis → bactericidal

hypoclorous acid (HClO or HOCl)

NaOCl mode of action:

____________ reaction by HOCl → _____________ → antimicrobial/ inhibits cell metabolism

chloramination

chloramines

NaOCl volume = ____-____ cc per canal

3-5

methods to avoid NaOCl extrusion (3)

1. irrigating needle loosely placed inside canal moving up-and-down to prevent binding

2. side-vented needle

3. depth of insertion

3. depth of insertion

solution travels < ____ mm ahead of tip

1 mm

NaOCl interactions:

1. Dentin

↓ antimicrobial activity

NaOCl interactions:

2. EDTA

↓ free chlorine → ↓ tissue dissolving ability

NaOCl interactions:

3. Chlorhexidine

makes 4-chloroaniline (PCA) orange precipitate

NaOCl interactions:

4. Presence of tissues

↓ bactericidal effect

a synthetic digluconate salt & protease inhibitor

chlorhexidine

chlorhexidine is [anionic/cationic]

cationic

what is the pH of chlorhexidine

5.5-7

chlorhexidine is _______________ at a high concentration (2%)

bactericidal

chlorhexidine is _______________ at a low concentration (0.12%)

bacteriostatic

does chlorhexidine dissolve tissues?

no

does chlorhexidine remove the smear layer?

no

substantivity

such a readily uptake and release of chlorhexidine leads to substantive antimicrobial activity

chlorhexidine interactions:

1. NaOCl →

2. EDTA→

parachloraniline (PAC)

white ppt salt of CHX

EDTA liquid solution = ____-____%

15-17%

EDTA propterties (2)

1. chelating agent (self-limiting)

2. antimicrobial (limited)

EDTA mode of action:

chelating agent removes

smear layer

chelating agent removes smear layer:

→ ____-____ microns in thickness, even into tubules _____ microns

→ smear layer = ________ + ________ debris

1-2

40

organic + inorganic

EDTA interaction with ________ → ↓ its tissue dissolving capcity by removing free chlorine

NaOCl

EDTA use ______ ( ____ min rinse) in canal preparation to remove smear layer

followed by last copious rinse with ________

once

1 min

NaOCl

lubricants (2)

1. liquid form glycerin

2. paste or gel form

liquid form of glycerin: spin _________ with a file to deliver it to the _______ area

CCW

apical

EndoGel: ____% EDTA and ____% chlorhexidine gluconate

15%

2%

rotary files require the use of ________ form lubricant for torque reduction in ________ blocks

liquid

plastic

is the irrigation regimen at MUSC binding or non-binding?

non-binding

irrigation regimen at MUSC:

____-____ mm from WL

1-3 mm

irrigation regimen at MUSC:

flow rate = ____ mL/min

4 mL/min

irrigation regimen at MUSC:

volume = ____-____ mL/canal

3-5

irrigation regimen at MUSC:

final rinse = _______ (1 mL) → _______ → _______ → dry with paper points

EDTA

NaOCl

saline

irrigation regimen at MUSC:

master cone fit after?

master cone fit before?

last NaOCl

saline irrigation