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Perio Chapter 3
Terms in this set (39)
Dental Biofilm can be characterized
as a microbial community that develops on a tooth or root surface that is embedded in a matrix of polymers derived from bacteria and saliva.
Bacterial cells represent
15 to 20 percent of biofil volume, with glycocalyx, composed predominately of water and anqueous solutes representing the remaining 75 to 80 present of the volume.
As a dental biofilm develops
the host mounts an infammatory response as a result of the bacterial challanges from the dental biofilm at the tooth/ginigival interface, resulting in inflammatory perdontal disease.
Exopolysaccharides (EPS) produced by bacteria in the biofilm
make up 50 to 90 percent of the dry weight.
First event of biofilm development
adsorption of molecules to the tooth surface. These molecules are derived mainly from salivia, but subgingivally originate from the gingival cervicular fluid.
the conditioning film, reversible adhesion occurs between the charge on the microbial cell surface and the charge present on the conditioning surface.
Microbes collect on the conditioning film
either passivley through salivary flow or gingival cervicular flow, in some case of few motile species, by their own transport.
When colonizers multiply
there is an increase in biomass and synthesis of exopolymers to the form a biofilm matrix.
Over 700 hundred
bacterial species resides within the oral cavity.
Shift hypothesis: some diseases are due to a decrease in the number of beneficial symbionts and/or an increase of in the number of pathogens .
Within the mouth in the transition from periodontal health to disease
there is an or microbiota shift from a population that is predominately gram-posittive anerobes to a population predominated by gram-negative anaerobes.
Biofilm present when the gingiva is healthy and noninflamed consists
mainly of gram-positive, saccharolytic and facultative aerobic bacteria.
Streptococci, Actinomyces, Veillonella, Bacteroids
Charaterized by a shift from a streptococcus-dominated plaque to an actinomyces-dominated plaque. deveopling gingivitis has been associated with increased numbers of actinomyces israelii and bacteriodes, especially porphyromonas gingivalis. Gingivitis has also been associated with an increase in motile bacteria and spirochetes.
Streotocci and actinomyces
and may comprise 85 percent of the microbial flora in health.
Three red complex bacteria
porphyromonas gingivalis, treponema denticola, tannerella fosythia.
Gingivitis begins in
10 to 20 days and resolved with 1 week of renewed oral hygiene efforts.
Densely packed strongly adherent to tooth surface. Gram-positive rods, cocci, and filamentous bacteria. Facultative aerobic or facultative anaerobes. Removed by scaling and root planing. Less virulent. (ability to cause disease)
loosley packed, loosley adherent to soft tissue wall. Gram-negative, motile, anaerobic. Spirochetes, "bottle brush" type. More virulent (able to cause disease). Cannot be removed by scaling and root planing; needs to be surgically removed.
Free swimming in pocket (not a biofilm). Gram-negative, motile, anaerobic. Spirochetes and others. More virulent (able to cause disease). Removed by flushing.
A thin film derived from salivary glycorproteins that form over the surface of a clean tooth when exposed to saliva.
Phase 1: initiation
Begins 1 to 2 days of plaque accumulation with no removal techniques. The microorganisms form as individual clones that extend both laterally and perpendicularly from the tooth surface to form parallel, palisading layers of bacteria. The colonies of bacteria are gram-positive cocci and rods, including streptococcus mutants and streptococcus sanguis.
Begins 2 to 4 ays after abstaining from daily toothbrushing or leaving individual areas undisturbed. Zone obliterated: the marginal band thicker. The plaque masses provide the base of the next phase of colonies to infiltrate. The next bacteria to form are gram-postive rods and gram-negative cocci. The space between the layers provides an anaerobic evironment for the arrival of anaerobic and facultive anaerobic bacteria. The cocci still dominate the plaque, however, filamentous forms and sleder rods compete for space. the matrix begins to form around the bacterial colonies derived mainly from salivary material, exudates from gingival cervicular fluid (GCF) and intermicrobial substances.
Strict or obligated anaerobic bacteria
Live without oxygen; nonoxygen utilizing bacteria.
Begins on days 4 to 7 with an increase in filamentous bacteria. Plaque extends coronally and thickens: PMNs increase in crevice. As the plaque matures, vibrios filaments such as Actinomyces species binds with cocci such as Streptococcus sanguis.
Phase 111: Continued
On days 7 to 11 early signs of inflammation observable in the gingiva. The inflammation is easily reversed by plaque removal. Inflammation with ___________ of the gingiva. Bacteria migrate subgingival and piggyback apically.
thrive in the depths of subgingival biofilm.
Days 14 to 21
Vibrios and spirochetes remain prevalent in the depths of the mass. The growth, accumulation, and pathogenicity of subgingival plaque are strongly influenced by the presence of supragingival dental plaque. Inflammation of the gingiva caused by supragingival plaque causes welling (edema) and gingival enlargement which alters the anatomic relationship between the tooth surface and the gingival margin and allows bacteria to invade the subgingival space to form subgingival plaque on the root surface. Subgingival space protected from oral cleansing mechanisms. The micrpbiota of subgingival plaque is generally more anaerobic, more gram-negative, more motile, and more asacchrolytic (incapable of breaking down sugars). The elimination of subgingival plaque is critical to prevention of periodontal disease.
incapable of breaking down sugars.
inflammatiory lesion that resides in the mucosa around an implant.
inflammation continues and affects the supporting bone around an implant
Both peri-mucositis and peri-implantitis
begin with biofilm formation
Scaling and root planning (SPR) considered
gold standard for treating periodontitis, however, the desired treatment outcomes of resolution of inflammation and a decrease in probing depths may not occur. The clinician may consider the use of antimicrobials as an adjunct to scaling and root planning.
Adjunt to SPR, biofilm must also be disprupted, can be used for chronic and agressive periodontitis, attached biofilms cannot be removed with mechanicaL debridement. The biofilm itself offers protection of drug-sensitive microorganisms by neighboring commensal bacteria that can produce a neutralizing or drug-degrading enzyme, such as the production of betalactamase, which inactivates penicillin-based antibiotics.
Can inactivate penicillin-based antibiotics.
After removal of subgingival biofilm
within 2-7 days the bacterial mass of dental biofilm starts to recolonize, streptococcus recolonizes rapidly, whereas the red complex bacteria return slowly.
Dental biofilm are the primary factor in
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