New Flashcards
(30 cards)
What is a biofilm?
A biofilm is a thin layer composed of biological material adhering to a surface.
What constitutes a microbial biofilm?
A microbial biofilm is a layer of microorganisms that adhere to a surface.
What is an aerosol?
An aerosol is the pulverized state of microorganisms that become airborne from a surface.
What types of surfaces do microbial biofilms adhere to more easily?
Microbial biofilms adhere more easily to solid surfaces, especially unpolished, calcified, and metallic surfaces.
What are biotic surfaces in the context of dental biofilms?
Biotic surfaces include oral mucosa, enamel, and cementum surfaces.
What are abiotic surfaces in the context of dental biofilms?
Abiotic surfaces are those that occur on the inner surfaces of air-water pipes of dental devices.
What initiates dental plaque formation?
Dental plaque starts out as a layer of biofilm.
Which gene encodes the biofilm formation of S. mutans?
The brpA gene.
What is the role of the brpA gene in S. mutans?
It encodes BRP, a protein that facilitates attachment to dental hard tissues.
Under what condition can S. mutans and S. sanguis form biofilms?
They require >250 mM glucose in the environment.
What happens to bacterial diversity when a biofilm forms on the cheek or mucosa?
S. salivarius attaches first, followed by an increase in number and variety of bacteria.
What is the structure of a microcolony in a biofilm?
Each microcolony is usually a cluster of pure bacteria.
What surrounds bacterial clusters in a biofilm?
An adhesin layer thickens and engulfs the bacterial clusters.
What is the purpose of grooves formed by bacterial cells in a biofilm?
They allow circulation of water and nutrients between bacterial islets.
How does biofilm formation affect microbial resistance?
Microorganisms become resistant to antimicrobials when in biofilm form.
Which organism is known to form biofilms on root canal walls?
Candida.
What is the MIC value for fluconazole against Candida biofilms?
28 μg/ml.
What is a significant risk associated with dental practice water systems?
They can be easily contaminated with microorganisms.
What are the characteristics of water systems in dental units?
They consist of closed pipes that open only to the water tank and aerator.
What is one recommended type of water for cooling instruments in dental environments?
Distilled water.
What happens when air flow is applied to water at sufficient pressure?
Water molecules break off and scatter as aerosols.
What is pulverization in dental practice?
The mixing of focused air and water to create droplets.
Which dental devices create droplets during operation?
- Ultrasonic scalars
- Sonic tool cleaners
- Rotary head tools
- Air-water sprays
- Airflow devices
- Air compressors
True or False: Droplets formed during dental procedures can carry infectious particles.
True.
