Disinfection of impression materials

2) In dipping and Immersion technique:

• Methods of disinfection ( Spraying, Immersion and Photodynamic therapy).

• Disinfection or sterilization?

Disinfection and sterilization are both decontamination processes but

What is the difference?

1) spraying technique:

Disinfection of Impression Materials

we will follow the previous procedures except fully immersion or dip immersion in disinfectant for recommended exposure time.

• Importance of disinfection of dental impressions

• Methods of disinfection of dental impressions

Disinfection is the process of eliminating or reducing harmful microorganisms from inanimate objects and surfaces.

Sterilization is the process of killing all microorganisms.

• Rinse under running tap water.

• Trim excess impression material.

• Why to disinfect, source of infection and infection categories

• Introduction.

3) Photodynamic therapy:

• Disinfection or sterilization?

Dental impressions are among the items that are considered potentially infectious.

• Why to disinfect, source of infection and infection categories.

Def: A topical treatment of pathogens that involves the use of a photoactive dye (photosensitizer), which is non-toxic when not exposed to light and activated by light of a specific wavelength in the presence of oxygen.

• Chemical disinfectants.

Dental impressions are contaminated with patient saliva or blood. Such fluids can contain viral and bacterial pathogens, including HIV and hepatitis A, B, and C viruses.

• Methods of disinfection ( Spraying, Immersion and Photodynamic therapy).

The new method of photodynamic disinfection with GaPc1 as photosensitizer was 100% efficient in C-silicones, A-silicones and polyethers, but not in alginates (40%).

• disinfect the impression.

Impression materials fall into the semi critical instruments, they need to disinfected (not sterilized)

• Compatibility of disinfectants with impression materials.
• Conclusion.

• insert the impression in a plastic bag.

• Compatibility of disinfectants with impression materials

• Chemical disinfectants

• Compatibility of disinfectants with impression materials

• Chemical disinfectants

2) Are they all used?

3) ZOE and Compound impressions:

1) Their Killing mode?

- After water wash the microbial count decreased to 48.5% while after sodium hypochlorite disinfection microbial count decreased to 99.99%.

Some are contraindicated:

- need friction (ex: alcohol).

-Carcinogenic ( ex: formaldehyde).

-low level action (ex: ammonium quaternary compounds).

Current ADA recommendations for ZOE is disinfection via immersion in a 1:213 Iodophor or 2% Glutaraldehyde solution.

2) Are they all used, drawbacks?

3) The best ones:

- As irreversible hydrocolloids are composed of 80% of water they are subject to the phenomena of imbibition (absorption of water) and syneresis (evaporation of water).

While Compound impressions reportedly can be disinfected via immersion in a 1:10 sodium hypochlorite solution or with an Iodophor.

- Sodium hypochlorite

-Gluteraldehydes

3) The best ones.

• Compatibility of disinfectants with impression materials

• Compatibility of disinfectants with impression materials

• Chemical disinfectants

1) Killing mode:

1) Alginate impressions:

2) Elastomeric impressions:

- Disinfection via immersion in dilute hypochlorite or Iodophor is recommended with short time exposure.

• Block release of cellular components:

Ex: gluteraldehyde, formaldehyde.

Rubber-base silicone impressions are disinfected adequately by immersion in an Iodophor, diluted hypochlorite solution, chlorine dioxide, glutaraldehyde, or complex phenol for the time required for tuberculocidal activity.

• Poisoning protoplasm ( Loss of vital components of cell ):

Ex: Phenols, Alcohols and Ammonium quaternary compounds.

Phenols with a high alcohol content, for example, can desiccate some impression materials.

• Cell oxidation:

Ex:Halogenous disinfectants

• Conclusion

Wax Bites and Wax Rims:

Office/Lab communication:

Disinfected using an iodophor, chlorine dioxide, or sodium hypochlorite spray by a "spray-wipe-spray" technique.

Communication between the dentist and the laboratory is essential to ensure that appropriate disinfection protocols are implemented without overlap.

Afterwards wax bites can be enclosed in a sealed plastic bag for the proper contact time.

Impression trays:

Impression trays should be rinsed thoroughly under running water to remove residual blood and saliva.