P2-ENDO LEC- CHAPTER 6

overpacking the sterilizer

what is the most common cause for inadequate sterilization?

heat-sensitive indicators

are useful to indicate that a package has been sterilized, but not to indicate sterility

- autoclaving

- pressurized heated chemicals

- dry heat

- cold chemicals

what are the approved methods of sterilization?

cold chemicals

- only used for items that cannot be heat sterilized

what method of sterilization is not recommended because its time cycle is difficult to monitor?

cold sterilants

requires extended soak times and would require rinsing in sterile water to remove traces of the disinfectant. not recommended because it is poisonous and harmful to patients

30 minutes at 250°F and 15 PSI

what is the usual autoclaving cycle?

20 minutes at 273°F and 30 PSI

what is the cycle for flash sterilization?

72% ethanol and 0.23% formaldehyde

in a Chemiclave chemical vapor sterilizer, what is used in place of water?

20 minutes at 270°F and 20 PSI

what is the cycle for Chemiclaves?

1 hour at 375° F

what is the cycle for dry heat sterilizers?

Cox sterilizer

uses forced hot air at 375 fahrenheit in 6 minutes

glass beads or salts

were used to transfer dry heat to endodontic canal instruments.

Glutaraldehyde, strong peroxides, o-phthalaldehyde

examples for high level disinfectants

high level

level of disinfectant for all microbes except spores

immersion

method of using high level disinfectants

intermediate level

level of disinfectant for:

Mycobacteria, not spores

Most fungi and most viruses

surfaces with blood

for what surfaces are intermediate level disinfectants used for?

Quaternary ammoniums with alcohol, chlorines, phenolics, iodoforms

examples of intermediate level disinfectants

low level

level of disinfectant for:

All bacteria except mycobacteria and spores

Some fungi and some viruses

surfaces without blood

what surfaces are low level disinfectants used for?

Quaternary ammonium, some phenolics, some iodoforms

examples of low level disinfectants

High level

what level of disinfectant are cold sterilizers?

1. dental unit switches

2. light handles

3. chair controls

4. EPT

5. thermal pulp testers

where should fresh barriers be placed on?

because disinfection occurs rapidly, not allowing bacteria to adapt quickly

why is bacterial resistance to disinfection less likely to occur, compared to antibiotic resistance?

1. instrument has broken through the wrap

2. wrap has been exposed to fluids and may wick into the sterile side of the package

what are the indications for resterilization?

1. weekly use of strong chemicals

2. continuous use of weak chemicals

3. 20- to 30-second flush between patients

what are the methods of cleaning dental water lines?

infected pulp tissue

can serve as a source for aerosol-borne biocontaminants

1. TB

2. SARS (severe acute respiratory syndrome)

3. Legionnaires' disease

4. Influenza

airborne transmission accounts for the spread of what diseases?

Guayule rubber proteins

a new latex glove material that has low allergenic potential

examination-type gloves

gloves that may harbor microbes from the point of manufacture or from contamination at the point of use.

hand lotions

these are able to degrade the rubber of gloves, so they are used only until after treatment has concluded for the day

substantivity

a property of chlorhexidine to bond to skin and maintains antibacterial action longer than other surgical scrubs

sodium hypochlorite (full strength)

the only agent that dissolves pulp tissue

to disinfect gutta percha cones

what is another use of sodium hypochlorite

1 minute to 1% concentration

5 minutes to 0.5% concentration

how do you disinfect gutta percha cones with sodium hypochlorite

true

true/false

endodontic files require sterilization before treatment

hepatitis B

influenza

measles

mumps

rubella

varicella

what are the needed vaccinations for dental staff

1. gloves

2. sterile technique

__________ should be considered only a barrier for staff protection. Patient protection comes from careful attention to _____________

mouthwash before every treatment

means of reducing bacteremia before every treatment

7 minutes

what is the tissue contact time for sodium hypochlorite to dissolve 75% of pulp tissue?

disinfectant bath

what is used if time is not enough to clean instruments immediately to prevent drying of foreign material on the instrument?

heavy puncture resistant gloves

what is used/worn if scrubbing is the only feasible means of cleaning instruments?

1. sharps (needles, scalpel blades, endodontic instruments, anesthetic cartridiges)

2. items soaked in blood or saliva

example of regulated medical waste

PPE (gloves, mask, garb) and barriers

examples of unregulated medical waste

mercury separators

removes heavy metal before entering the city waste system

nitrous oxide scavenger

removes gas exhaled by the patients

false

true/false

nitrous oxide scavengers completely eliminates exhaled gas from the office

it causes congenital abnormalities

what is the risk of nitrous oxide scavengers if the gas is exposed to patients, which is why it should be piped outside rather than into the mechanical room?

prions

glycoproteins found on cell surfaces

stainless steel

prions have an affinity for what surfaces?

sodium hydroxide

a certain caustic chemical used to kill prions

formalin and glutaraldehyde

what chemicals are prions resistant to?

incineration

what is the best way of disposing contaminated files?

Hepatitis C

for which kind of hepatitis is there no available vaccine

cold chemicals

recommended for instruments that cannot be sterilized

1. formaldehyde is emitted

2. instruments will be smelly

3. an odor is released when instruments are heated

what are the disadvantages of chemiclave?

glass bead

used for chair-side sterilization in between patient appointments

450F in a few seconds!

what is the sterilization cycle using glass beads?

ultrasonic cleaner

common method to clean instruments prior to sterilization, also known as cavitation

iodophor

are broad spectrum disinfectants effective against most pathogens

2% glutaraldehyde

most appropriate high level chemical disinfectant

>20 mins: disinfection

6-10 hours: sterilization

what are the immersion times for glutaraldehyde