Dental OSCE (Objective Structured Clinical Examination) Practice Exam

Which high-level disinfectant is capable of killing spores?

1. Formaldehyde

2. Glutaraldehyde

3. Hydrogen peroxide

4. Chlorine bleach

The correct answer is: Glutaraldehyde

Glutaraldehyde is recognized as a high-level disinfectant with the capability to kill spores. Its effectiveness is particularly valuable in healthcare settings where sterilization of medical instruments is critical. Glutaraldehyde functions by disrupting the cellular structure of microorganisms, including bacterial spores, which are among the hardest forms of microorganisms to eliminate. Through a process called alkylation, glutaraldehyde modifies the proteins and nucleic acids in the microbes, ultimately leading to their death. This property makes it essential for the disinfection of heat-sensitive instruments that cannot withstand the higher temperatures of autoclaving. Other disinfectants may also have strong antimicrobial properties, but they do not possess the same level of efficacy against spores as glutaraldehyde. For instance, formaldehyde is also a powerful disinfectant and can kill many pathogens; however, its effectiveness against spores is somewhat limited compared to glutaraldehyde. Hydrogen peroxide and chlorine bleach are excellent disinfectants for a wide range of pathogens but are typically not classified as high-level disinfectants with sporicidal capabilities. Thus, glutaraldehyde stands out as the correct choice for a high-level disinfectant effective against spores.