2. MICROBIAL SHIFT AND PERIODONTITIS
Berezow A B, Darveau R P
Perio 2000 2011;55:36-47
GUIDED BY:
DR. AMIT GOEL
PRESENTED BY:
DR. VIRSHALI GUPTA
PG 2ND YEAR
6. ADVANTAGES OF BIOFILM
Increased ability to
attach to surfaces---by
pili and by extracellular
polymeric substance
(Davey ME et al 2000).
Metabolic cooperation,
wherein the waste
product of one bacterial
species serves as the
food source for another.
Resistance to
antibiotics that easily
kill bacteria growing in
planktonic culture.
Avoid the host immune
system. Antibodies
unable to perforate the
matrix (Fux CA et al)..
8. The bacterial composition of plaque remains relatively
stable despite regular exposure to minor environmental
perturbations.
This stability (microbial homeostasis) is due to a dynamic
balance of both synergistic and antagonistic microbial
interactions.
However, homeostasis can break down, leading to shifts in
the balance of the microflora, thereby predisposing sites
to disease.
The subgingival microflora shifts from being mainly Gram
positive to being comprised of increased levels of
obligately anaerobic, asaccharolytic Gram-negative
organisms.
BIOFILMS AND HUMAN HEALTH
9. Over 700 sps have been detected in the oral cavity, over half of which have never
been cultivated. (Aas JA 2005)
Substantial diversity in the content of the microflora between individuals and
between different oral sites within the same individual.
Dietary changes combined with poor hygiene can cause a shift in the
composition of the oral microflora.
Bacteria also appear to be associated with oral health. For instance, a positive
association has been observed between oral health and the presence of Veillonella
(Kumar PS et al 2006) or Capnocytophaga ochracea (Riep B et al 2003).
11. MICROBIAL SHIFT LEADING TO PERIoDONTITIS
GRAM POSITIVE AEROBES GRAM NEGATIVE ANAEROBES
Gradually changes the symbiotic host–microbe relationship to a
pathogenic one.
Prevotella intermedia
Fusobacterium
nucleatum
P. Gingivalis
Tannerella forsythia
Treponema denticola
12. However, recent research
has challenged this
paradigm. periodontal
pathogens such as P.
gingivalis and T. forsythia
could also be frequently
isolated from healthy
controls. –Riep et al 2009
ON THE CONTRARY…
Kumar et al. 2006 directly
contradicted the existing
pattern when they observed
that the gram-negative
bacterium Veillonella was
associated with periodontal
health, while the gram
positive anaerobe Filifactor
alocis was associated with
disease.
14. An adjunct to scaling and root planing, and they can be applied
locally or administered systemically.
Local, sustained-release minocycline significantly improved patient
outcomes when compared to scaling and root planing alone.
Using multiple antibiotics simultaneously leaves a patient
susceptible to developing an oral yeast infection or experiencing other
severe systemic adverse effects.
Antibiotics do not directly suppress the host inflammatory response
that is largely responsible for the tissue destruction.
antibiotics
15. ANTISEPTICS
Chlorhexidine, bleach (sodium hypochlorite),
povidone-iodine can be used as an
alternative to antibiotics.
Chlorhexidine was more effective than
minocycline at destroying P. gingivalis
biofilms in vitro.
P. gingivalis was completely eradicated after
30 minutes of exposure to chlorhexidine,
povidone-iodine or Listerine.
Do not address host inflammation.
16. Suppresses the
inflammatory
response by MMPs.
Doxycycline most potent
inhibitor of MMPs. Sub -
antimicrobial doses of
doxycycline used as an
adjunct to SRP showed
improvement in clinical
parameters.
NSAIDS &
bisphosphonates,
Proresolving agent
resolvin E1 could
have potential as
HMTs.
HOSTMODULATIONTHERAPY
17. PHOTODYNAMIC THERAPY
ROS react with essential cellular components
such as DNA, proteins and lipids, leading to cell
death.
Photosensitizers used include dyes (such as
methylene blue, acridine orange and toluidine
blue O),
APDT destroy P. gingivalis, it also inactivates a
virulence-associated protease, as well as the
destructive host inflammatory mediators TNF-α
and IL-1β.
18. The use of probiotics to
treat diseases associated
with a shift in the
microflora. Hence proposed
for the treatment of
periodontitis.
Research showed that when a
mixture of streptococcal sps
was applied to the teeth of
dogs as an adjunct therapy
following root planing, there
was a delay in the re-
colonization of periodontal
pathogens and reduction in
inflammation.
(Teughels W et al 2007)
Use of a mouth rinse
containing Bacillus subtilis or
oral administration of tablets
containing Lactobacillus
salivarius reduces the
number of periodontal
pathogens.
(Mayanagi G et al 2009,
Tsubura S, 2009)
PROBIOTIC THERAPY
19. ASSESSING THE EFFICACY OF TREATMENT
treatment altered the
content of the microflora
and helped to resolve the
host inflammatory
response.
BIOLOGICALLY CLINICALLY
Reduction in probing
pocket depth and
clinical attachment
gain
DNA–DNA checkerboard technique relies upon hybridization of labelled
probe DNA to the genomic DNA isolated from bacterial cells in patient
plaque samples. This technique has been used to determine the nature of
the microbial biofilm before and after treatment of periodontitis.
20. A reduction in the number of red and orange complex bacteria, as well as a reduction in
the number of sites colonized by these pathogenic bacteria, following various forms of
treatment. ---Haffajee et al 2009
Following SRP and weekly supragingival plaque removal for 3 months, the microbial
profile of the treated patients was similar to that of periodontally healthy people.
Thus, the DNA–DNA checkerboard technique is vital to both researchers and clinicians
in characterizing the nature of the biofilms associated with periodontal health and
disease.
Microarrays and real-time PCR can demonstrate that inflammatory genes were down
regulated in periodontitis patients following therapy. In addition to analyzing the
effectiveness of treatment, this method may also help reveal which host genes are most
responsible for the development and persistence of periodontitis. ---Wang et al 2015
ASSESSING THE EFFICACY OF TREATMENT
21. CONCLUSION
• Oral dysbiosis, or a shift from beneficial symbiotic bacteria to pathogenic
bacteria, is at least partially responsible for the development of
periodontitis. However, despite great advances in our knowledge of the
underlying microbial basis of this disease, the fact remains that
periodontitis has multiple etiologies that have yet to be fully understood.
• Thus, while a microbial shift is known to play a significant role in the
development of periodontitis, genetic, immunological and environmental
factors must also be investigated in order for clinicians and researchers to
fully understand disease progression.
Microbial shift more commonly known as dysbiosis refers to the concept that sum diseases are due to dec in the number of beneficial symbionts or an inc in the number of pathogens. And periodontitis a biofilm ass inflammatory disease of the periodontium, is a major cause of tooth loss.
Periodontitis appears to have multiple etiologies but the most studied of which are microbial and immunological. The primary microbial factor contributing to disease is a shift in the content of the oral microflora, while the primary immunological factor is the destructive host inflammatory response.
Bill costerton in 1978 coined the term biofilm. Biofilms generally take the form of polymicrobial communities attached to biotic or abiotic surfaces. Clean abiotic surface immersed in liquid tend to attract and conc nutrients whereas biotic surfaces such as plant and animal tissues can themselves be a source of nutrients for microorg. Biofilm is formed when microorg attaches to and grow on abiotic or biotic surfaces. The initial attachment is usually irreversible and often involves attachment by flagella, fimbrae or other cell str. This is followed by production of an exopolymer which makes the attachment irreversible. Growth ass within the biofilm is notuniform, channels develop which made incorporation of fresh nutrients and oxygen. Metabolic activities in the biofilm causes changes in the micro env. For example o2 gradient develop that permits anerobic metabolism on interior and aerobic metabolism on exterior. Nutrient and ph gradient also produced.
Extracellular polymeric substance consists of polysacc, proteins, lipids, nucleic acids and other polymers and help the bac adhere to the surface as well as to each other.
In the dental plaque biofilm streptococci ferment carbohydrates to lactic acid which is then degraded to propionate and acetate by Veillonella sps.
3. because antibiotics find it difficult to penetrate the sticky extracellular polymeric substance, or slow growing subpopulations of bac found in biofilm are less susceptible to antibiotics. Because gradients of nutrients and oxygen exist from top to bottom of biofilms and these gradients are ass with the dec bac metabolic activity and inc doubling times of the bacterial cells, it is these more or less dormant cells that are responsible for some of the tolerance to antibiotics.
The regulation of expression of specific genes through the accumulation of signaling compounds that mediate intercellular communication (Prosser 1999)
Synergestic: s. sanguis, s. mitis, Veillonella, streptococcus, capnocytophagia
Antagonist: bac of red complex.. P.gingivalis T.forsythus T.denticola..
Ob anerobes..p. gingivalis. F. nucleatum. vellonella parvula. A isrellali
Asaccharolytic.. P. gingivalis
In the case of the oral cavity , attempts to characterize the normal microflora have met with challenges.
Minocycline passes directly through the lipid bilayer or passively diffuses through porin channels in the bacterial membrane. Tetracyclines like minocycline bind to the 30S ribosomal subunit, preventing the binding of tRNA to the mRNA-ribosome complex and interfering with protein synthesis. Another meta-analysis confirmed this result and found that minocycline and tetracycline were the most effective local adjunctive therapies when measured in terms of probing depth reduction and clinical attachment level gain. Dynacin Apo-minocycline Cap 50mg Aknemin Apo-Minocycline Klinomycin Minoderm Minomycin Minopen Minox Minoz Vectrin
The positively charged chlohex mol is attracted to –velly charged phospholipids in the cell wall . Chlrohex binds to the cell wall causing it to rupture. The rupturing of cell wall causes fluid to leak leading to lysis and cell death.
Significant increase in CAL gain when compared to SRP alone for sustained-release Chlorhexidine chips , a different meta-analysis showed that chlorhexidine was not as effective as minocycline or tetracycline in probing depth reduction or clinical attachment level gain.
Pro resolving- drugs that promote the resolution of inflammation as opposed to merely blocking it. E1 derivative of omega 3 fatty acid and was shown to regenerate lost tissue and bone in a p gingivalis induced model of periodontitis in rabbits. Bisphosphonates are a class of drugs that prevent the loss of bone mass, used to treat osteoporosis and similar diseasesFosamax Plus D cholicalciferol Actonel .. Calc cRBONate
reactive oxygen sps……………..ANTIMICROBIAL PHOTODYNAMIC THERAPY.. Utilizes singlet o2 and free radicals by a light activated photosensitizer to kill microbes. The photo chemical process is initiated by a low power light with short wavelength to excite the photosensitizer. The ground substance photosensitizer absorbs light resulting in a singlet state that can lose energy by flurescence or undergo intersystem consisting to a triplet state with longevity. The later state lead to a photochemical reaction that induces singlet o2, free radicals, and superoxide which are cytotoxic toxicity inducing microbial killing. '"leukocytic pyrogen"', "'leukocytic endogenous mediator'", "'mononuclear cell factor'", "'lymphocyte activating factor'" and other names, is a cytokine proteinThis cytokine is an important mediator of the inflammatory response, and is involved in a variety of cellular activities, including cell proliferation, differentiation, and apoptosis. Pro inflamma
Probiotic .. Substance which stimulates the growth of micro org those with beneficial properties..live micro org contain in the food .. They remain intact throughout the digestive process, and deliver healthy bac directly to the large intestine………..prebiotics are a dietary fibre that trigger the growth of bac having favourable effects on intestinal flora. Since probiotic donot stimulate metabolic activity they provide a diff set of benefits than prebiotics… pro.. Block pathogenic bacterial effects by producing bactericidal substances .. Regulate immune responses by enhancing the innate immunity and modulating pathogen induced inflammation… regulate intestinal epithelial cell survival. Enhancing barrier func and stimulating protective responses.