Exam 2 Flashcards
what are the 5 methods of measuring gingivitis/periodontitis?
plaque index
gingival index
probing depth/pocket depth
gingival cervicular fluid
bleeding on probing
what is plaque index?
a measure of accumulated dental plaque on different surfaces of teeth, usually a score is calculated for an individual tooth
what is gingival index?
a measure is calculated for an individual tooth, using redness as an indicator of inflammation
what is probing depth/pocket depth?
increased depth is indicative of attachment loss, specifically referring to the PDL
what is gingival cervicular fluid?
an inflammatory exudate derived from periodontal tissues, composed of serum and locally generated materials such as inflammatory mediators and antibodies directed against dental plaque bacteria
what is bleeding on probing?
results from dilation, engorgement, and thinning of the epithelium, rupture more easily
what are the most subjective measures for gingivitis status?
plaque index
gingival index
probing depth
what are the best measures for gingivitis status?
bleeding on probing
gingival cervical fluid volume
What are the 3 major differences between Plaque Induced Gingivitis and Periodontitis?
1) there is no alveolar bone loss associated with gingivitis
2) here is no attachment loss of the PDL with gingivitis
3) gingivitis is reversible, unlike periodontitis
Can someone have attachment and or bone loss and still have gingivitis? If so under what condition?
you can have gingivitis associated with a site that has had previous bone or attachment loss but is not progressing
What type of bacteria benefit from primary colonizers and the increasing reduced environment of the developing biofilm (decreasing oxygen)?
Gram negative bacteria – facultative rod bacteria
1) Outline the Loe et al experiement:
2) What were the main results?
3) What was a limitation/caveat?
1)
- Stopped oral hygiene (whole mouth) until inflammation was achieved (14-21 Days
- Resumed brushing and interdental gingival massage until baseline measures were obtained
- Bacterial assessment were obtained through impressions and using bacterial smears
- Beginning of non-brushing period was associated with increases cocci bacteria
- Days later filamentous and rod associated bacteria were overserved along with large amounts of cocci.
- Near peak inflammation vibrios and spirochetes and some cocci were detected
- in health, commensal organisms were gram positive cocci bacteria (like strep species)
2)
- Plaque maturation produced changes in the environment that allowed new species of bacteria to grow
- Accumulation of plaque was the cause of gingival inflammation
3)
- Staining is not indicative of specific species, just types of bacteria
what were the major points of the Soc. et al 1998 study?
1) what had been already established?
2) what technique was developed?
3) result?
4) what was the caveat of this study?
1) It had been established that microbe complexes exist in subgingival plaque and were associated with varying levels of gingival health/diseases severity
2)
- Socransky et al. developed a technique “Checkboard” DNADNA Hybridization in order to identify and classify microbial complexes associated with gingival health and disease
- Use Specific digoxigenin-labeled whole genomic probes or 16S rRNA-based oligonucleotide probes directly conjugated to alkaline phosphatase (turns black when released – bound probe).
3) 5 major bacterial complexes associated with clinical measures
4) Caveat: Only probes for 43 different taxa were used and varied between Genus and Species from subjects with periodontitis
these two studies are foundational in gingival health and disease research. What evidence in your lecture suggests that they may be out of date?
they are older studies? (1965 and 1998)
What are the major shifts in types of bacteria from Healthy to Gingivitis?
as the biofilm matures the redox potential of the environment decreases
–> favors the growth of anaerobic and facultative bacteria species
–> increase in gram negative bacteria
–> emergence of gram negative facultative rod bacteria
What is significant about microbial complexes defined by Sorcransky?
1) What is the Orange complex associated with?
2) What is the Red Complex associated with?
1) orange = associated with gingivitis (more like red complex, but differenct clinical measures (BOP, PD))
2) red = associated with periodontitis
Is the epidemiology of gingivitis well established? Why or Why not?
Periodontal epidemiology is deficient
Most conditions are lumped together, as explained with the different types of gingivitis
describe gingivitis
reversible inflammation in the marginal periodontal tissues
decribe chronic periodontitis
severity of disease consistent with plaque and calculus. Slow to moderate progression of tissue destruction. Aggravated by systemic conditions (i.e. diabetes) or environmental factors (i.e. smoking).
describe necrotizing periodontal diseases
“Trench mouth”
painful condition with a fusospirochaetal etiology
different from other periodontitis because of PAIN
Describe the Koch’s Postulates and its limitations within the periodontal diseases.
1) The suspected pathogenic organism should be present in all casesof the disease and absent in healthy animals.
* ▸Some perio pathogens present in healthy individuals and sites
2) The microorganism must be isolated from a diseased organism and grown in pure culture.
* ▸Most oral species are fastidious and are difficult to isolate and cultivate in lab (i.e. Treponema)
3) The cultured microorganism should cause disease when introduced into a healthy organism.
* ▸Lack of good animal model systems for perio
4) The microorganism must be reisolated from infected host and shown to be the same as the original
describe specific plaque hypothesis
can be used to explain?
Pathogenicity of plaque depends on the presence of, or relative increase of, specific microorganisms
- Not all plaque bacteria are equally pathogenic
- Can be used to explain A. actinomycetemcomitans in localized aggressive periodontitis
describe non specific plaque hypothesis
Non-specific: Periodontitis caused by dental plaque as a whole, accumulating over time on the teeth.
- All plaque bacteria equally capable of causing disease
describe ecological plaque hyposthesis
Ecological: Disease is a result of an imbalance in the total microbiome due to ecological stress, resulting in an enrichment of disease-related microorganisms
- Consistent with specific plaque hypothesis in recognizing that different plaque bacteria have varying pathogenic potentials
- Focused on ecological perturbation and emphasizes the microbiome as a whole
- Disease can be prevented by targeting the putative pathogens and also by interfering with the environmental factors
Define keystone pathogen and its significance in disease progression. (Be prepared to provide examples).
keystone pathogen: a low abundance species which can disproportionately modulate the host response
- When bacteria acts independently, it has little impact on the host
- Overtime, bacteria assemble into heterotypic communities –> some cause disease, others don’t (can be pro inflammatory and produce toxic components), growth controlled by the host
- If host is infected with keystone pathogen, it can disrupt the community –> becomes pathogenic (dysregulation of immune surveillance, altered composition and total counts, increased expression of virulence factors, overgrowth of pathobionts, disruption of tissue homeostasis)
- Examples:
Understand the concept of homeostasis and dysbiosis in relation to health and disease
Combined synergy and dysbiosis is more severe than the sum of the individual species acting alone
