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periodontal disease

- disease of the supporting structures of the teeth

- usually caused by PLAQUE

gingivitis

inflammation confined to the gingiva

periodontitis

inflammatory disease resulting to the destruction of periodontal ligament and alveolar bone

1. facultative

2. aerobic

colonizers of the infant mouth: within hours after birth

anaerobic

colonizers of the infant mouth: second day

imbalance or DYSBIOSIS

shift in microbial community

Streptococcus salivarius and Streptococcus mitis

first and most dominant microbiota

Veillonella spp. Neisseria spp. Actinomyces spp. and Staphylococcus spp.

also among the first colonizers of the oral cavity

S. sanguinis, Lactobacillus spp. and S. oralis

microbiota after tooth eruption

S. oralis, S. anginosus, S. mutans, S. sobrinus, S. gordonii

oral streptococci (microbiota after first year of life)

fusobacterium spp. and Prevotella spp.

microbiota in young children

oropharynx

most organisms can survive in the _____ only when they adhere to either the soft tissues or the hard surfaces

pocket epithelial cells in vivo

in periodontal pockets, studies have shown high numbers of bacteria attached to ?

desquamation

ensures that the microbial load on mucosal surfaces is kept relatively low

ectodermal interruption

protected by junctional epithelium

crevicular fluid

aids in protection of periodontal pocket

P. gingivalis and P. intermedia

isogai and coworkers reported a significantly lower adherence rate of ________ and ______ strains to gingival epithelial cells in rats that were resistant to gingivitis compared with susceptible rats

periodontopathogens

there is a theory that teeth are the primary habitat for ________

A. actinomycetemcomitans and P. gingivalis

disappeared from the oral cavity after tooth extraction

P. intermedia and other black - pigmented Prevotella spp

remains from the oral cavity after tooth extraction

S. mutans

as opposed to _____ which is mostly considered as an obligate periphyte

obtaining sufficient nutrients to support growth

major struggle faced by bacteria

1. biofilm

2. polysaccharides, proteins, and nucleic acids

- three‐dimensional, structurally organized multispecies communities

- composed of microbial cells encased within a matrix of extracellular polymeric substances, such as ? (3)

1. bacterial microcolonies

2. water channels

biofilms contain:

1. diet

2. smoking

3. diabetes

4. age

factors affecting distribution and metabolism of the oral microbiota

plaque

- an example of a biofilm (heterogenous and fluid filled channels)

- sessile microcolonies get nutrients by diffusion from the water channels

- biofilm matrix functions as a barrier

glycoproteins

- important component of pellicle

- initially coats a clean tooth surface, but they also become incorporated into the developing plaque biofilm

plaque

structured, resilient, yellow- grayish substance that adheres tenaciously to the intraoral hard surfaces, including removable and fixed restorations

materia alba

soft accumulations of bacteria, food matter, and tissue cells that lack the organized structure of dental plaque

calculus

hard deposit that forms via the mineralization of dental plaque and that is generally covered by a layer of unmineralized plaque

supragingival margin

- at or above the gingival margin

- forms first

marginal gingiva

direct contact with gingival margin

subgingival plaque

below the gingival margin

1. coronal part – filaments

2. apical part - spirochetes, cocci, and rods

composition of the subgingival plaque

pellicle formation

- layer of organic material covering ALL surfaces of the oral cavity

- within seconds
- made up of peptides, proteins, glycoproteins (keratins, mucins, proline- rich proteins,

phosphoproteins, histidine-rich proteins, and other molecules that can function as

adhesion sites (receptors) for bacteria

1. thin basal layer

2. thicker globular layer

2 layers of pellicle

1. bacterial transport

2. initial adhesion

3. strong attachment

colonization of bacteria: 3 phases

primary colonizers

- first 4-8 hrs

- streptococcus spp.

- provide binding sites for other bacteria

1. haemophilus spp, neiserria spp

2. actinomyces spp, veilonella spp

primary colonizers:

- obligate aerobes: ???

- facultative anaerobes: ???

bacterial transport

- to the surface of the pellicle

- more of salivary flow or mechanical contact

initial adhesion

long- and short-range forces, including van der Waals attractive forces and electrostatic repulsive forces

strong attachment

- interaction between microbial adhesins and pellicle receptors

- many proteins in the acquired pellicle can act as receptors for streptococci, including α-amylase, acid proline-rich proteins, statherin, and salivary agglutinin glycoprotein gp340

fusobacterium nucleatum

- can co-adhere to most oral bacteria

- acts as an important bridging organism between early and late colonizing species

gingival margin and interdental spaces

plaque formation starts at? _____ and ______

1. grooves

2. cracks

3. perikymata

4. pits

plaque formation may also originate in?

anaerobic and asaccharolytic

bacteria that predominate in mature plaque are?

quorum sensing

bacteria secrete a signaling molecule that accumulates in the local environment and triggers a response such as a change in the expression of specific genes once they reach a critical threshold concentration

clinically healthy gingiva

predominant gram (+) bacteria or facultative anaerobes

gingivitis

- there is a shift

- an increase in gram (-) bacteria

- more anaerobic bacteria

- influx of fusobacteria, filaments, spiral forms, and spirochetes

exogenous / classical infection

not part of normal flora

endogenous / opportunistic

part of normal flora

virulence

measure of how pathogenic a bacterium is

pathogenicity

ability to cause disease

direct tissue destruction

virulence factors themselves damage the host cell/tissue and the extracellular matrix

direct tissue destruction

virulence factors, such as toxins and proteases, released/produced by the bacteria degrade/destroy ECM or cause cell death or inhibit a host cell

indirect tissue destruction

virulence factors induce host tissues to damage themselves

indirect tissue destruction

virulence factor would induce a host cell (fibroblast, macrophage, etc) to produce a chemical mediator that will degrade the ECM or cause death of host cell

non-specific plaque hypothesis

direct relationship between the total number of accumulated bacteria and the amplitude of pathogenic effect

specific plaque hypothesis

a single pathogenic species is the cause of inflamed periodontal disease

ecologic plaque hypothesis

both the total amount of dental plaque and the specific microbial composition of plaque may contribute to the transition from health to disease

virulent clonal theory

says that there can be different genotypes/strains of the bacteria which are of varying pathogenicity

1. virulence pathogen

2. local environment

3. susceptible host

3 factors that favor the progression of Gingivitis to Periodontitis:

dental calculus

- mineralized plaque

- formation depends on amount of plaque and secretion of salivary glands

supragingival plaque

- can be creamy-whitish to dark yellow or even brownish mass of hardness

- can usually be found on lingual surface of mandibular anteriors buccal aspect of maxillary first molars

saliva

supragingival plaque: mineral salts in?

inflammatory exudate

subgingival plaque: mineral salts in?

subgingival plaque

- not visible unless gingiva has receded; can be found by tactile sensation

- brownish-to-black calcified hard mass with a rough surface

- around 0.5mm calculus free zone coronal to the apical extension of the periodontal pocket

liesegang rings

- concentric rings

- reflect successive phases of mineralization

- crystalline in structure (calcium phosphate)

false

calculus causes periodontitis? true or false?