DEN 101 | WEEK 2

What is the general rule for surfaces that may have contact with saliva, blood, or aerosols?

Assume they contain live microorganisms and require disinfection.

What two surface categories did CDC guidelines distinguish in dental settings?

Clinical contact surfaces and housekeeping surfaces.

What are clinical contact surfaces?

Surfaces that can be directly contaminated by patient contact.

What are housekeeping surfaces?

Floors, walls, sinks, and other surfaces with lower risk of disease transmission.

List factors that determine the level of contamination on a clinical contact surface.

Degree of patient contact, hand contact type/frequency, how often touched, potential aerosol/spatter contamination, and other microorganism sources.

In what order should you clean areas during disinfection?

Start with the most heavily contaminated areas, then move to less contaminated areas.

Name the three categories under the clinical contact surface umbrella.

Touch surfaces, transfer surfaces, and splash/spatter/droplet surfaces.

What is a touch surface?

A surface that is directly contaminated by touch.

What is a transfer surface?

A surface in contact with contaminated items (e.g., an instrument sits on it).

What are splash, spatter, and droplet surfaces typically?

Housekeeping surfaces where aerosolized material may land on a countertop or sink.

Why are touch surfaces cleaned first?

They are directly contaminated and more heavily contaminated than splash/spatter/droplet surfaces.

Can touch, transfer, and splash/spatter/droplet surfaces be identified in an operatory image?

Yes; handles are an example of touch surfaces.

How should disinfectants ideally perform?

Kill a wide variety of bacteria, have minimal toxicity, not damage surfaces, be odorless, inexpensive, and easy to use.

Do any products meet all ideal criteria for disinfectants?

No.

What are two methods of dealing with surface contamination in dental settings?

Surface barriers and pre-cleaning with disinfection between patients.

If a barrier is touched, what must be done?

It becomes contaminated and must be pre-cleaned and disinfected.

What are single-use items?

Items used once and disposed of; they are not sterilized for reuse.

Give examples of single-use items.

HVE tips, saliva ejectors, needles, scalpel blades, disposable impression trays.

Where should single-use items be disposed of?

Regular office trash, except for sharps which require special disposal.

Are there known cases of cross-infection from treatment room surfaces?

No known cases, but pre-cleaning and disinfection are required by OSHA.

What standard requires cleaning and disinfection between patient visits in dental settings?

OSHA Bloodborne Pathogen Standard.

What does pre-cleaning accomplish?

Removes bioburden (thin layers of saliva or blood) to improve disinfectant effectiveness.

When is disinfection performed relative to pre-cleaning?

After pre-cleaning.

Name two methods of surface disinfection.

Spray-wipe-spray and wipe-discard-wipe.

Describe the spray-wipe-spray method.

Spray the surface, wipe to pre-clean, spray again to disinfect.

Describe the wipe-discard-wipe method.

Use one wipe to pre-clean and another to disinfect.

What does disinfection do?

Kills disease-producing microorganisms remaining after pre-cleaning.

What is a key difference between disinfection and sterilization?

Disinfection does not kill spores; sterilization kills all microbial life including spores.

How is a disinfectant defined?

A chemical applied to inanimate objects.

How is an antiseptic defined?

A chemical applied to living tissue to reduce microorganisms.

What type of disinfectants should be used in dentistry?

EPA-registered hospital disinfectants with tuberculocidal claims.

Why is Mycobacterium tuberculosis significant in disinfection?

It is highly resistant, so disinfectants effective against TB work on less resistant microbes.

What is the typical contact time for EPA hospital disinfectants?

Around 10 minutes; the surface must remain moist.

What are immersion disinfectants used for?

Disinfection of instruments by immersion.

What precautions are required when using immersion disinfectants?

PPE and a container with a lid to minimize fumes.

Name examples of immersion disinfectants.

Glutaraldehyde, chlorine dioxide, and ortho-phthalaldehyde (OPA).

How long do immersion disinfectants take to work?

6–30 hours.

What happens when new items are added to an immersion disinfectant solution?

The timer resets.

What is the purpose of a high-volume evacuator?

Reduces the risk of saliva escaping and aerosolization.

How should evacuator tubes and pipes be cleaned?

Daily with detergent or water; special traps cleaned and replaced regularly.

How should housekeeping surfaces be cleaned?

With detergent and water or a low-level to intermediate EPA-registered disinfectant.

How often should surface disinfectant solutions be refreshed?

Fresh daily; unused solution discarded.

Why should carpeting and cloth furnishings be avoided in operatories?

They harbor bacteria and fungi; hard surfaces are easier to clean.

What steps are needed for blood or bodily fluid spills?

PPE, pre-cleaning, and disinfection.

Is there evidence of disease transmission from housekeeping surfaces?

No evidence, but OSHA mandates cleanup.

What does CDC recommend for disinfecting surfaces?

EPA-registered hospital disinfectant with appropriate activity level based on spill and porosity.

What is greener infection control?

Aims to reduce environmental impact by conserving resources and using more eco-friendly PPE and practices.

What is the difference between disinfection and sterilization (as clarified in notes)?

Disinfection kills microorganisms remaining after pre-cleaning; sterilization kills all microbial life, including spores.

What is a disinfectant, in simple terms?

A chemical applied to inanimate objects to kill microbes.

What is an antiseptic, in simple terms?

A chemical applied to living tissue to reduce microorganisms.

Which agency registers disinfectants?

EPA (Environmental Protection Agency).

What is a common staining disinfectant?

Iodophors may stain surfaces.

What is a potential drawback of synthetic phenol disinfectants?

They can leave a residual film on surfaces.

What is the common term for sodium hypochlorite?

Bleach.

Which disinfectant is not effective in the presence of blood or saliva?

Alcohol.

How is chlorine dioxide classified in the provided notes?

It is classified as both a surface disinfectant and a chemical sterilant.

What is an example of a low-level disinfectant used for general housecleaning?

A low-level disinfectant (in context of general cleaning).

What is a barrier made of to cover surfaces?

A fluid-impervious or fluid-resistant material such as chair covers, keyboard covers, or tape.

What happens if a barrier is removed improperly?

The clean surface underneath may become contaminated.

What is a

Placeholder

What are the six links in the Chain of Infection?

Infectious Agent, Reservoir, Portal of Exit, Mode of Transmission, Portal of Entry, Susceptible Host.

What is an Infectious Agent?

The germ (bacteria, virus, fungus, parasite, prion) that causes disease; must be virulent.

What is a Reservoir in the Chain of Infection?

Where the germ lives and grows (humans, animals, water, surfaces, equipment).

What is the Portal of Exit?

How the germ leaves the reservoir (coughing, blood, saliva, skin contact).

What is the Mode of Transmission?

How the germ spreads (direct, indirect, airborne, droplet, bloodborne, food/water, fecal-oral).

What is the Portal of Entry?

How the germ enters a new host (mouth, nose, eyes, skin, bloodstream).

What is a Susceptible Host?

Someone with weak immunity or no resistance (elderly, sick, unvaccinated, chemo patients).

What happens if any link in the Chain of Infection is broken?

Infection cannot spread.

What is an Acute infection?

Quick, severe symptoms, short-lasting (e.g., cold).

What is a Chronic infection?

Long-lasting, ongoing (e.g., HIV, Hepatitis C).

What is a Latent infection?

Hidden, flares up sometimes (e.g., cold sores, shingles).

What is an Opportunistic infection?

Normally harmless germs cause illness when immunity is weak (e.g., during chemotherapy).

What is Inherited immunity?

Natural immunity present at birth.

What is Active natural immunity?

Get the disease, recover, body makes antibodies.

What is Active artificial immunity?

Vaccine stimulates antibody production.

What is Passive natural immunity?

Antibodies from mother (placenta, breast milk).

What is Passive artificial immunity?

Antibodies given through injection (antiserum).

What are the main Transmission modes from Patient to Dental Team?

Direct contact, droplets, indirect contact.

How can Dental Team to Patient transmission occur?

Rare, but can happen if provider has cuts/lesions.

How is Patient to Patient transmission prevented in dentistry?

Sterilization, barriers, handwashing.

How can Dental Office contribute to Community transmission?

Contaminated impressions, lab items, or staff leaving with dirty PPE.

What is Community → Dental Office → Patient transmission?

Contaminated water lines carrying biofilm.

What does the CDC do?

Provides guidelines and recommendations to prevent disease transmission (not laws).

What does OSHA do?

Regulatory agency that enforces laws (e.g., Bloodborne Pathogens Standard).

What are Universal/Standard Precautions?

Treat all blood and body fluids (including saliva) as infectious every time.

What should you do after an Exposure incident?

Stop immediately; remove gloves; wash with soap and water; apply antiseptic + bandage; tell supervisor right away.

What is a puncture-proof sharps container?

Red, labeled with biohazard symbol; used to dispose sharps.

Why should you not cut, bend, or break needles?

To prevent needle-stick injuries.

Should you recap needles with two hands?

No; never recap with two hands—use one-handed scoop or a safety device.

What is the correct sequence after an exposure incident?

Stop; remove gloves; wash with soap and water; apply antiseptic + bandage; tell your supervisor right away.

What PPE items are listed for dental assistants?

Protective clothing, surgical masks, face shields, protective eyewear, disposable patient treatment gloves, heavy-duty utility gloves.

What is CDC’s recommendation about saliva ejectors and lip position?

Do not ask patients to close their lips tightly around the tip.

What risk does backflow from low-volume saliva ejectors pose?

Backflow can cause cross-contamination.

What does Latent infection mean?

Persistent infection with symptoms that come and go.

What is Direct contact?

Touching a patient’s blood or saliva.

What is Indirect contact?

Touching contaminated surfaces or instruments.

What is Droplet infection?

Infects mucosal surfaces of eyes, nose, or mouth.

What is Percutaneous exposure?

Enters through skin (needle sticks, cuts).

What is Permucosal exposure?

Contacts mucous membranes.

What is Occupational exposure?

Anticipated contact with blood or other infectious materials.