Microbiology of dental caries Flashcards
Describe dental biofilms
- A natural and beneficial part of the oral mucosa
- Diverse composition of bacteria, fungi and viruses
- Relatively stable composition
How do we characterise the oral microbiome in health and disease
Pathogenic vs beneficial micro organisms
How many species make up the dental bio film
can have as many as 300 in a single person
What is a microbiome
A group of organisms
What is desquamation
Shedding
What does desquamation allow for
reduction in microbial load on the mucosal surfaces
What makes dental biofilm unique
It has non shedding surfaces
Give examples of non shedding dental surfaces
- Teeth
- Dentures
- Implants
What problems can non shedding surfaces face
Heavy biofilm formation and build up if the bacteria isn’t controlled
How are microorganisms in dental biofilm organised
Structurally and functionally
List some key features of multi species biofilm
- Concerted and collaborative organisms
- Food chains
- Gradients present
- Matrix formation
- Cell- cell signalling
- Complex interactions occur to create balance
What are some of the beneficial qualities of biofilm
- The exclude extrogenous microbes providing colonisation residence
- Down regulation of potentially damaging pro inflammatory host responses
- Stimulates beneficial host responses
- Promotes host microbe balance
- Contributes to the salivary nitrate circulatory system
Name some healthy micro organisms
- Strep. Mitis/ oralis
- Actinomyces spp
- Haemophilus spp
- Neisseria spp
- Fusobacterium spp
Name a micro organism found in caries
Mutans streptococc
Caries is a m_______________ disease
Multifactorial
Why is caries described as multifactorial
As several factors play a role in the development of dental caries in an individual
list some factors that can lead to the formation of dental caries
- Key oral micro organisms must be present
- Environmental factors
- Susceptible host present
Give examples of some environmental factors that can cause dental caries
- Cariogenic diet
- Poor OH
- Reduced salivary flow
- Low/ no fluoride
- Non specific virulence traits
Give examples of bacteria found in dental caries
- Strep mutans
- Strep sobrinus
- Strep cricetus
- Strep rattius
- A neslundi
- A odontolyticus
- Lactobacillus spp
- Bifidobacterium
Describe mutans streptococci
- Gram positive cocci/ short rods
- Found on hard non shedding surfaces
- Implicated I the initiation of caries
Where does dental caries first begin to form
Just below the enamel surface- can appear as a white spot lesion
Describe Veilllonela Spp
- Is a lactate utilising micro organism
- Gram negative coccus
- Anaerobic
List some characteristics of cariogenic bacteria
- Transport sugar rapidly and produce acid rapidly
- Tolerate acid
- posses extracellular and intracellular polysaccharide
At what pH do mutans streptococci produce acid?
pH 3.9-4.2