Biofilm & Plaque Formation Pt.1 Flashcards
What are the early colonizers of the sterlie oral enviroment after birth?
low numbers of mainly facultative and aerobic bacteria
Why is it that before tooth eruption there is only faculative and anerobic bacteria?
Lack of niches to support anerobic; no crevices
At that time, the oral microbiota of newborns closely resembles the mother’s
what are the two microbiota possibilities?
- Birth canal= vaginal microbiota
- Cesarean section= mothers skin microbiota
From the second day, ____ bacteria can be detected in the infant’s edentulous mouth.
No teeth.
anaerobic bacteria
As exposure ot external enviromnetal microbal sources occurs in infants what happnes?
The number of oral bacteria increases gradually
What are the 2 first and most dominant oral microbes to colonize the oral cavity of newborn infants.
- Streptococcus Salivarius
- Streptococcus Mitis
Gram +, facultative anerobic resp.
Explaint the relationship of detection and growth of a microbe?
Detection does NOT mean growth.
Microbe may be there, but it may not be viable.
What are the 5 inital colonizing species of the oral microbiota?
- Streptococcus
- Lactobacilli
- Actinomyces
- Nesseria
- Varionella
Study living And No Vacations
What (generally) happens after tooth eruption?
more complex oral microbiota is established (more niches= more crevices)
What are three species that colonies teeth post tooth eruption?
- Streptococcus sanguinis
- Lactobacillus spp.,
- Streptococcus oralis.
SLO
What 5 streptococci species are found after the 1st year of life and can becomecariogenic?
- S. oralis
- Streptococcus anginosus
- mutans streptococci (Streptococcus mutans and Streptococcus sobrinus)
- Streptococcus gordonii
Oral Anguish must sob greatly
What 2 anerobes can be detected (does not mean growth) in young children?
- Fusiform Spp.
- Prevotella spp.
As more teeth erupt what occurs?
More bacterial growth, more species, more niches for adhearance of bacteria.
Hard surfaces
establishment of microbes, does not mean you exhibit the disease because . Bacteria has to overcome immunity of the host and their defenses.
Colonization
What are 3 red complex bacteria?
- P. gingivalis
- T. Forsynthia
- T. denticola
Most organisms can survive in the oropharynx only when they adhere to either what?
- Soft tissue
- Hard surfaces
What are ways in which bacteria that is not adheared to a hard surface or soft tissue can be removed by?
Protective mechanism
- Swallowing, mastication, or blowing the nose
- Tongue and oral hygiene implements
- The wash-out effect of the salivary, nasal, and crevicular fluid outflow
- The active motion of the cilia of the nasal and sinus walls
Stagnation is required for bacteria to settel of hard surfaces
Bacteria growth in which the bacteria does not settel or stick to surfaces; turbid broth.
not required to settel.
Planktonic Growth
Bacterial growh in which it sticks and settels on to hard surfaces
Biofilm growth
Where can biofilms not form?
Mucosa!
it NEEDs to be a hard surface
What is the first virulence factor of biofilm bacteria?
allows a bacteria to be more successful in a niche
Being able to stick to surfaces!
Fimbrae, adhesion receptos
The ability of a bacterium to what? Is crucial for the induction of infectious diseases like gingivits and periodontitis
adhere to its host
Oral bacteria and especially pathogenic bacteria, such as P. gingivalis and Aggregatibacter actinomycetemcomitans have a large battery of what?
virulence factors
Wider range.
What is (B) and what is E? What is next to (B)? Cloud area?
B= emeshed fibrin
Next to B= bacillus bactera
Cloud area= agreggating matrix produced by bacteria (proteins excreted out, providing essential formation of plaque)
E= erythrocyte (RBC)
What are the 6 major ecosytems of the oral cavity?
- Supragingical hard surfaces
- Subgingival regions adjacent to hard surfaces
- Buccal-palattal epithelum + epithelium of floor
- Dorsum of tongue
- Tonsils
- Saliva
What niche?
hard surfaces (teeth, implants, restorations, and prostheses)
intraoral and supragingival
(above gingival line)
the periodontal/peri-implant pocket (characterized by the presence of crevicular fluid, the root cementum or implant surface, and the pocket epithelium)
Subgingival region adj to hard surface
(below gingival line)
Worst place for bacteria to get in is ? What is this called.
Blood; bacteremia.
In advanaced periodontitisbacteria penetrate what 2 things sturctures to enter the connecitve tissue?
Penetrate the:
1. Pocket epithelium
2. Basment lamina
The capacity of adhesion of P. gingivalis varies. Explain
Normally always in oral microbiota
* **Healthy pt= **low levels, resistance to adhesion
* Chronic Periodontisit= lots of adhesion, becuase enviroment is condusive to the organism. Less resistance.
suggested that teeth are the primary habitat for what?
Periodontopathogens
Explain what removal of teeth in pt. wit severe periodontitis does to bacteria?
key pathogens such as Aa and P. gingivalis dissapear from oral cavity BUT P. intermedia & prevotella spp. remained in lower numbers
implantation of new tooth can result in re-colonization of the bacteria.
Because not all bacterial infection was taken care of.
What signals that inflammation is still ongoing?
Gingival recession
Eradiaction fo all bacteria and niches in the mouth even with full denture weares is what?
Nearly impossible. Some bactera will always find a niche/crevice to hide out in.
Post full extraction A. actinomycetemcomitans and P. gingivalis are what?
remain colonizers of the oral cavity, but when teeth are lost, the relative numbers of these bacteria decrease
Explain cariogenic species hypothesis?
S. mutans cells in the saliva or on the tongue are derived from the biofilm present on the teeth.
Hard surface present? Cariogenic species there.
If all teeth are extracted they will hide out and wait. Reappar after denture insertion.
Also can be detected in pre-dentate children
What are 3 attachements of plaque?
- Tooth attached plaque (hard surface)
- Unattached in between
- Epithelial associated
Bad hygiene, bad oral health=
quroum sensing
Endose bacterial growth
Good hygiene, but lapse in health=
quroum sensing
no profound growth
bacteria can understand each other
sense presence of others= environment is good for growth.
No bacteria around= hide away and not grow
Quorum Sensing
Biofilm bacteria are often up to 1000 times more resistant to antimicrobial agents than what counterpart?
Layered biofilm= hard to penetrate
planktonic counterparts
What are 3 way in which bacteria in biofilms interact?
Brazil!
- Mutually ben; ones waste is anothers food
- Compete; secrete antibimcrobials like inhibitory peptides (bacteriocines) or H2O2
- Cell signaling & DNA exchange btw.
In a biofil, Introduction of 1 organim with resistance =
all eventually have resistance.
Biofilms are?
single word answer
heterogeneous; lots of variation
WHat are 4 things common to many biofilms?
- Contain microcolonies
- Water channels (basic circulatory system; remove waste products, brign fresh nutrients to deeper layers)
- Surface Structures; fronds help ddispiate energy of fluid flowing over biofilm
- Heterogeniatiy of species forms steep chenical gradiaents (pH, oxygen, create dif microenviroments within)
commonly found in biofilms,
can form a primitive circulatory system that removes waste products and brings fresh nutrients to the deeper layers of the film!
Bacteria close to channels take what they want.
Bring water down without bringing oxygen
Water Channels
can dissipate the energy of fluid flowing over the biofilm (saliva) and lead to the rapid blockage of vessels.
Surface structures, such as fronds
Microbial populations on the surfaces of teeth
heterogeneous in structure, with clear evidence of open fluid-filled channels running through the plaque mass
Dental Plaque
(attached) microcolonie
Sessile
In dental plaques explain how nutrients reach microcolonies within the biofilms
by diffusion from the water channels to the microcolony, rather than from the matrix.
The biofilm matrix functions as a barrier. Substances produced by bacteria within the biofilm are what?
retained and concentrated
which fosters metabolic interactions among the different bacteria.
In dental plaque the bacteria exist and proliferate within the ____ ____ through which the channels run.
intercellular matrix
What is arrow?
10 Day old Supra-gingival plaque. Inflmaattion showing.
Dental Plaque
intercellular matrix consists of organic and inorganic materials derived from
- saliva
- gingival crevicular fluid
- bacterial products.
Dental Plaque matrix
- polysaccharides
- proteins
- glycoproteins
- lipid material
- DNA.
Organic Compoind if Matrix
Dental Plaque matrix
originates from crevicular fluid(self produced), has been identified as a component of the plaque matrix.
Albumin
Dental Plaque matrix
consists of debris from the membranes of disrupted bacterial and host cells, bacterial vesicles, and possibly food debris
Lipid mateiral
Dental Plaque matrix
initially coats a clean tooth surface, but they also become incorporated into the developing plaque biofilm.
Pellicle
Dental Plaque matrix
What is an important component of the pellicle?
Glycoproteins from the saliva
Dental Plaque matrix
produced by bacteria also contribute to the organic portion of the matrix. They play a major role in maintaining the integrity of the biofilm
Polysaccharides
Biofilm bacteria adhear to what specifcially?
THE pellicle! not the tooth enamel.
Washing and brushing removes pellicle, which is absorbed by saliva and swallowed.
Dental Plaque matrix
; predominantly calcium and phosphorus, with trace amounts of other minerals such as sodium, potassium, and
Inorganic Components
Dental plaque matrix
The source of inorganic constituents of supragingival plaque is primarily what?
Saliva!
What happens to plaque as mineral content increaes
Mineral content increase= calcification of dental plaque into calculus
Where is calculus normally found?
areas of the dentition adjacent to salivary ducts
* Lingual mandibular incisors & canines
* Buccal Max 1st
Why is it that calculus is found adjacent to salivary ducts
reflects the high concentration of minerals available from saliva in those regions.
The inorganic components of subgingival plaque are derived from what?
crevicular fluid (a serum transudate; high in albumin)
Subgingival calculus is typically what color? and why?
dark green or dark brown
reflects the presence of blood products (heme) that are associated with subgingival hemorrhage.
Explain steps of calclus formation
- Tooth hard surface
- Saliva Flowing
- Pellice attaches to tooth
- Biofilm bacteria come in and attach to pellicle
- Starts to thicken
- Establish matrix
- Calcifies due to increase mineralization= calculus
What does this depict?
Supragingival calculus on buccal surface of max molars adjacent to the orfice of parotid duct max 2nd molar
are supra and subgigical calculus mutally exclusive?
You can do either or and both.
a structured, resilient, yellow-grayish substance that adheres tenaciously to the intraoral hard surfaces, including removable and fixed restorations.
Dental Plaque
What feature of dental plaque makes it makes it impossible to remove plaque by rinsing or with the use of sprays.
Tough Extracellular matrix
soft accumulations of bacteria, food matter, and tissue cells that lack the organized structure of dental plaque and that are easily displaced with a water spray.
Materia alba
a hard deposit that forms via the mineralization of dental plaque and that is generally covered by a layer of unmineralized plaque
Calculus
Explain pattern of mineralization in calculus
Mineralizes bottom up, sticker on top (unminerlization)
Look
Look
In subgingival plaque on a single tooth surface can be how much microorganims?
can exceed 10^9 cells.
In periodontal pocket how much microorganims in a healthy crevice compared to a deep pocket?
Healthy Crevice= 10^3
Deep Pocket= 10^8
plaque is found at or above the gingival margin
- Supragingival plaque
when in direct contact with the gingival margin, it is referred to as
Marginal Plaque
Plaque is found below the gingival margin, between the tooth and the gingival pocket epithelium.
Subgingival plaque
Why is it that subgingival microbiota differs in composition from the supragingival plaque
Primarly due to Local availibility of blood product and low redox potential (anerobic enviroment)
What is one of the main characterisitcs on an anerobic enviroment?
low reduction–oxidation (redox) potential
because no final e- acceptor
Periodontopathgens are fastidious strict anerobes this means they what?
In terms of disease causing not oxygen usage
contribute little to the initiation of disease in shallow gingival pockets.
= Found DEEPER; preffered habitat deep periodontal pocket
Explain the relationship of actinomyces and streptococci
They congregate via adhesion-receptor interactions
Initial colonizers (strep) then areggators (actinomyces) bring in more
What bacteria genus were shown to form a framework for dental plaque?
How?
Corynebacterium spp
Extends from the tooth surface through to outer layers of the biofilm
What microrganims dominate in tooth associated cervical plaque?
filamentous microorganisms dominate
but cocci and rods also occur.
gram-positive rods and cocci, including S. mitis, S. sanguinis, Actinomyces oris, Actinomyces naeslundii, and Eubacterium spp
in deeper pockets filamentous dissapear
Explain the trend of filamentous microorganisms in terms of amount
Most dominating in Cervical plaque, less in deeper parts of periodontal pockets, virtually absent in apical portion of plaque
Explain the apical plaque mass
Apical border is seperated from JE by a layer of host Leukocytes
Gram (-) anerobic rods
What happens to line of leukocutes at JE as apical plaque mass matures?
failure in the defensive line. Requires more policelmen= more inflammation this occurs over time
Explain trend from material alba to chronic periodontisits
- Material alba,
- Pellicle fomation
- Dental plaque formation
- Dental plaque mineralization into calculus
- Periodontitis, to chronic periodontitis)
All surfaces in the oral cavity, including the hard and soft tissues, are coated with a **layer of organic material known as the acquired **
Pellicle
180 peptides, protiens, and glycoprotiens keratins, mucins, proline-rich proteins, phosphoproteins (e.g., statherin), histidine-rich proteins, and other molecules that can function as adhesion sites (receptors) for bacteria.
At what point can a salivart pellicle be detected on clean enamel surfaces?
within 1 minute after their introduction into the mouth.
Explain why the pellicle is not a passive adhesion matrix
Many proteins retain enzymatic activity when they are incorporated into the pellicle, and some of these, such as peroxidases, lysozyme, and α-amylase, may affect the physiology and metabolism of adhering bacterial cells
