The document classifies chemical disinfectants into three categories based on their effectiveness against different microbes: high-level disinfectants like ethylene oxide gas and glutaraldehyde solutions which can inactivate bacterial spores; intermediate-level disinfectants like formaldehyde and chlorine compounds which can destroy microbes like tubercle bacilli but not spores; and low-level disinfectants with narrow antibacterial activity like quaternary ammonium compounds and detergents which are not suitable for disinfecting dental impressions. It also provides recommendations for disinfecting various dental impression materials using iodophors or diluted sodium hypochlorite for 10 minutes.

6. High-level Intermediate level Low-level
Capable of inactivating bacterial
spores and all other microbial
forms, an essential criteria for
high-level disinfectants like
ethylene oxide gas or
glutaraldehyde solutions.
Namely formaldehyde , chlorine
compounds , iodophors, alcohols,
and phenolic compounds, destroy
microbes like tubercle bacilli, but
they do not inactivate spores.
With narrow antibacterial
activity namely, quaternary
ammonium compounds,simple
phenols ,and detergents , which
are unacceptable for impressions
disinfection
Chemical disinfectants can be classified into three categories based on their efficiency against vegetative
bacteria, tubercle bacilli, fungal spores, and viruses.

7. IMPRESSION MATERIAL DISINFECTANT AGENT DURATION
Alginate Iodophors and diluted sodium
hypochlorite
10 minutes
Compound Iodophors and diluted sodium
hypochlorite
10 minutes
Polyether Iodophors and diluted sodium
hypochlorite, complex phenolics
10 minutes
Polysulphide Iodophors and diluted sodium
hypochlorite, complex phenolics
10 minutes
Silicone Iodophors and diluted sodium
hypochlorite, complex phenolics
10 minutes
Agar Iodophors and diluted sodium
hypochlorite
10 minutes
Zinc-oxide eugenol Iodophors 10 minutes

8. 1.IODOPHOR

9. 2.GLUTARALDEHYDE