Chapter 17: Dental soft deposits, Biofilm , calculus & stains Flashcards
a thin, acellular tenacious film formed of proteins, carbohydrates, and lipids.
acquired pellicle
when does formation of pellicle formation begin
upon exposure to saliva
the pellicle begins to form and is fully formed within 30 to 90 minutes
composition of pellicle
glycoproteins, selectively adsorbed by the HYDROXYAPATITE of the tooth surface.
types of acquired pellicle
- subgingival
2. supragingival
clear, translucent, insoluble, and not readily visible until application of a disclosing agent.
supragingival pellicle
can become embedded in tooth structure, particularly where the tooth surface is partially demineralized or rough due to abrasion.
subgingival pellicle
The pellicle plays an important role in the maintenance of oral health as it :
protects, lubricates, and acts as a nidus of attachment for the bacteria and subsequent calculus on the tooth surfaces.
Extrinsic factors that may interfere with pellicle formation and maturation include:
- Abrasive toothpastes.
- Whitening products.
- acidic foods and beverages.
composed of microorganisms, their genetic make-up, and the environments found in the oral cavity.
microbiome
is a dynamic, structured community of microorganisms, encapsulated in a self-produced extracellular polymeric substance (EPS) forming a matrix around microcolonies
dental biofilm
composed of polysaccharides, proteins, and other compounds; it acts to protect the biofilm from the host’s immune system and antimicrobial agents.
matrix
referred to as acquired pellicle, dental biofilm,materia alba, food debris/
soft derposits
stages of biofilm formation
- formation
- bacterial multiplication
- matrix formation
- biofilm growth
- maturation
components of EPS
Polysaccharides
glucans
fructans or levans
dietary sucrose.
during this stage
Biofilm formation begins with initial attachment of planktonic bacterial cells to the pellicle on the tooth surface
during this stage of adhesion, the process is reversible.
stage 1 : Formation
during this stage Planktonic microorganisms attach themselves using cell adhesion structures such as fimbriae, pili, flagella, and adhesion proteins.
colonies produce EPS to firmly attach in an irreversible manner; rough surfaces will result in more rapid irreversible attachment.
stage 2- bacterial multiplication
during this stage Bacteria within the aggregate of cells continue to secrete EPS as bacteria multiply to form a matrix.
stage 3- matrix formation
provides a scaffold to anchor the bacteria together increasing adherence to dental and other structures and provide PROTECTION as the bacterial community continues to grow.
EPS
This stage is characterized by further development of the biofilm architecture to enhance the cell-to-cell communication process, also known as quorum sensing
stage 4 - biofilm growth
during this stage Bacterial colonies mature and release planktonic cells to spread and colonize other areas within the oral cavity
stage 5 - maturation
With undisrupted biofilm for approximately _ days, negative anaerobic bacteria growth is favored, which increased risk for dental ___ and _____
7
caries
gingivitis
on these days Early biofilm consists primarily of gram-positive cocci.
Streptococci, which dominate the bacterial population, include Streptococcus mutans and Streptococcus sanguinis.
1-2 days
on these days The cocci still dominate while increasing numbers of gram-positive filamentous form and slender rods join the surface of the cocci colonies along with more leukocytes.
2-4 days
on these days Filaments increase in numbers, and a mixed flora appears comprised of rods, filamentous forms, and fusobacteria with heavy accumulations of leukocytes
6-10 days
