Term
| What is the basic structural unit of biofilm? |
|
Definition
| The microcolony of specific species or mixtures of species. |
|
|
Term
| Why is detachment a programmed mechanism in biofilms? |
|
Definition
| Because this helps the bacteria survive through dissemination into other areas of the environment that are also hospitable to the species of the original colony. This is accomplished by breaking adhesins or having digestive enzymes breaking saccharides. |
|
|
Term
| The close proximity of cells allows for what processes to occur? |
|
Definition
| Nutrient gradients, gene exchange (horizontal transfer) and quorum sensing. |
|
|
Term
|
Definition
| The process where bacteria are able to communicate by pheromones or autoinduces, thereby signalling changes in adjacent cells to react in a way that allows for adaptability in the biofilm. |
|
|
Term
2 part T/F
1. Bacterial species are arranged randomly in mushroom shaped biofilms.
2. Chemical gradients in biofilms are linear. |
|
Definition
1 False. There is a rhyme and reason to species distribution in biofilm
2 False. An example of non-linear gradient is pH, which fluctuates greatly throughout the biofilm. |
|
|
Term
| How does living in a biofilm make it easier for cells to survive? |
|
Definition
1 They are protected from environmental stressors
2 Together they combat invading species
3 efficient nutient acquisition and metabolism |
|
|
Term
| Up-regulation of exo-polymer gene expression and glycolysis usually occurs when bacteria ________________ |
|
Definition
|
|
Term
| The ability of cells to acquire genetic material (as in horizontal gene transfer) is termed ________ _______ |
|
Definition
|
|
Term
| What is the interbacterial matrix mainly composed of? |
|
Definition
| Exopolymers (polysaccharides) and salivary glycoproteins |
|
|
Term
| Proteinaceous toxins produced by cateria to inhibit the growth of similar or closely related bacterial strains are ______________ |
|
Definition
|
|
Term
| Define universality in terms of oral bacteria. |
|
Definition
| Universality means the bacterial genera and species will be more or less equal among human oral environments throughout the world. |
|
|
Term
| What type of bacteria will first appear in someones mouth after they have completely sterilized their mouths? |
|
Definition
| The indigenous bacteria or microflora. These bacteria are also called resident, normal or commensal bacteria. |
|
|
Term
2 part T/F
1. Salivary bacteria are termed transients.
2. 50% of indigenous microflora are represented by just 20-30 species. |
|
Definition
1. True
2. False, ~95% of indigenous come from just 20-30 species |
|
|
Term
| Most children inherit mutans streptococci around age 3. Who gives it to them? |
|
Definition
| Their mothers. After this, their immune system will not tolerate other strains of indigenous bacteria from other people. |
|
|
Term
After being prescribed antibiotics, which infection are you most susceptible:
1. Leishmaniasis
2. Pseudomembranous candidiasis
3. Gingivitis
4. Schistomiasis |
|
Definition
| Pseudomembranous candidiasis (a fungal infection) will thrive when bacterial competition is reduced. |
|
|
Term
| What type of pathogens are inhibited by hydrogen peroxide? |
|
Definition
|
|
Term
| How is strep mutans pathologic effect changed by indigenous biofilms? |
|
Definition
| The biofilms will often make alkali products that neurtralize strep mutans acids. |
|
|
Term
What is the difference between the following hypothesis:
1 Specific plaque hypothesis
2 Specific ecology hypothesis |
|
Definition
| Specific plaque hypothesis posits that specific specific bacterial pathogens cause oral disease whereas spec ecology hypothesis subscribe to the theory that pathogenicity and virulence depend on the host, bacteria, and environment (the major controlling factor). |
|
|
Term
| Name some evidences for the specific ecology hypothesis. |
|
Definition
1. Glucan production go up upon s mutans attaching to a surface
2. Pathogenicity islands
3. Clonal variants.
4. Synergistic enhanced virulence.
5. Oral pollution. |
|
|
Term
| What does clonal variant mean? |
|
Definition
| The same bacteria exhibit different phenotypes depending on environmental stress. |
|
|
Term
| What aspect of biofilms exhibits horizontal gene transfer? |
|
Definition
| The pathogenicity islands show that biofilms serve as a gene reservoir for its associated species. This is evident in porphymonas gingivalis colonies. |
|
|
Term
Red complex bacteria virulence is best described by
1. Clonal variation
-or-
2. Synergistic enhanced virulence |
|
Definition
| 2. Synergistic enhanced virulence |
|
|
Term
| How do biofilm concepts affect dentists? |
|
Definition
| It affects the ways that we manage diseases and try to eradicate the biofilms. We also need to understand how to facilitate healthy biofilms by reducing pollutants |
|
|
Term
| What are examples of oral pollution? |
|
Definition
| An ecological disruption often caused by exogenous factors that stop our defense like smoking, medications and soft, sugary diets. |
|
|
Term
| How do biofilm concepts affect dentists? |
|
Definition
| It affects the ways that we manage diseases and try to eradicate the biofilms. We also need to understand how to facilitate healthy biofilms by reducing pollutants |
|
|
Term
| What are examples of oral pollution? |
|
Definition
| An ecological disruption often caused by exogenous factors that stop our defense like smoking, medications and soft, sugary diets. |
|
|
Term
| If we are looking at the plaque-tooth interface, which sides have more sugar? Acid? |
|
Definition
| More sugar on plaque side. More acid on tooth side. |
|
|
Term
| How do anaerobes live in the mouth in biofilms? |
|
Definition
| The facultative species (most strep) prevent oxygen from destroying the anaerobes. |
|
|
Term
| Which type of bacteria are more motile sub- or supragingival? |
|
Definition
|
|
Term
| When do most bacteria begin making acid? |
|
Definition
| After they receive polysaccharide. They use glucosyl transferase enzyme in order to metabolize the polysaccharide. This creates acid. |
|
|
Term
| What is the key determinate of architecture, exopolymer, or acid gradients? |
|
Definition
|
|
Term
| What is the daily source of plaque bacteria? Which teeth are most at risk? |
|
Definition
| Saliva is the major daily source. The teeth nearest the salivary entries are most at risk including buccal sides of max molars and lingual mandibular incisors. |
|
|
Term
| Which species are able to decrease acid? |
|
Definition
| Strep gordonii. this converts urea to ammonia which will reduce caries experience. |
|
|
Term
| What is the central premise of non-specific plaque hypothesis? |
|
Definition
| That if you have less plaque (regardless of microbial distribution) --> less pathology. Vice versa. The treatment therefore should be to decrease plaque always. |
|
|
Term
| Why are domestic cats a great example for microbial pollution? |
|
Definition
| Because domestic cats have a much different diet than they have evolved into having, they experience more periodontitis. |
|
|
Term
| Why is sucrose a pollutant? |
|
Definition
| We didn't evolve eating sucrose. The effect of sucrose is to increase the amount of S mutans affecting microbial population ecology and decreasing protective species. This causes increase in pit and fissure caries experience. |
|
|
Term
| Which bacteria adhere first and to what? |
|
Definition
| Strep usually are first to bind to the PELLICLE, which as lots of PRPs (proline-rich proteins). |
|
|
Term
2 statement T/F, Plaque Development:
1. After 12 hrs, strep sanguinis and oralis (facult anaerobes) dominate.
2 After 24 hrs, actinomyces (gm-) and veillonella, fusobacterium, prevoltella and porphymonas (gm+) appear. |
|
Definition
| 1. True, 2. False, These are the right bacterial species, but actinomyces is gm + and the others are gm- |
|
|
Term
| Over the period of 12 hrs - 5 days, what happens to the environment of plaque? |
|
Definition
| The oxygen levels decrease aiding proliferation of gm-, obligate anaerobes like spirochetes. |
|
|
Term
| How is strep mutans cohesion affected by dietary sucrose intake? |
|
Definition
| As sugar goes up, the s mutans makes more extracellular polysacharide (ECP) which aides in linking cells together. |
|
|
Term
| T/F: The binding of lipoteichoic acid in gm+ cells to pellicle and candida mannoprotein binding to soft tissues are examples of hydrophobic binding. |
|
Definition
|
|
Term
|
Definition
| Hidden receptor sites on a surface that can be degrades enzymatically. This degradation (by neuraminidase) can change the species of bacteria that can attach from S. sanguinis and oralis to Actinomyces. |
|
|
Term
| Why are there more saccharolytic cells in supragingival plaque? |
|
Definition
| Saccharolytic bacteria digest sugar. Supragingival plaque has low protein and high sugar. So, digesting sugar is more important. |
|
|
Term
| How do supra-gingival bacteria survive when nutrients are scarce? |
|
Definition
| They are able to store the sugars in the form of intracellular polysaccharide (ICP), which is glycogen-like storage polymer. They make lactic acid upon digestion of ICP. |
|
|
Term
| Which types of bacteria tolerate and make more acidic environments, sub- or supragingival bacteria? |
|
Definition
| Supragingival. This makes them more cariogenic and more gram+ |
|
|
Term
| Where does oral malodor come from? |
|
Definition
| metabolic byproduct of protein metabolism that is volatile and sulfur containing |
|
|
Term
Will the following conditions occur with protein or sugar metabolism?
high pH, calculus when above pH7, gm- anaerobes, odor production, gingival inflammation |
|
Definition
| Most likely from subgingival protein metabolism. |
|
|
Term
| How is lactobacilli able to live at such low pH? |
|
Definition
| It uses a proton pump H+/ATPase to be able to make it's own pH more neutral so its enzymes can still function |
|
|
Term
| What is the main source of ammonia that bacteria make? |
|
Definition
| Most ammonia comes from the metabolism of arginine or urea |
|
|
Term
| What event marks the end of the ability for the tooth to restore and remineralize itself? |
|
Definition
|
|
Term
Match the following:
1 Makes Cavity
2 cavity progression
a s mutans
b lactobacilli |
|
Definition
|
|
Term
| What is one cariogenic reason why we take radiographs more frequently for children than adults? |
|
Definition
| Caries progresses much quicker in children because of the thin layers of enamel and dentin. It only takes 3mo-1yr to go though enamel of primary teeth compared to 6mo-2yr in permanent teeth. |
|
|
Term
Which of the following is not a direct contributing factors to caries?
Susceptible tooth
cariogenic bacteria
cariogenic diet
failed immune resonse
time |
|
Definition
|
|
Term
| Which age group is most susceptible to caries: 4-6, teens, young adults, or elders? |
|
Definition
| TEENS. Young adults are least susceptible |
|
|
Term
2 part T/F
1. Prehistoric caries consisted mainly of interproximal caries, not occlusal caries.
2. Once sucrose was available in the 1800s interproximal caries rates increased dramatically. |
|
Definition
1 False: Prehistoric people had mainly root caries.
2 Trues |
|
|
Term
Imagine three mice were fed the following diets. Which were most susceptible to caries:
1. Lactose
2. Glucose
3. Sucrose |
|
Definition
| 3. Sucrose: the most cariogenic sugar for animals |
|
|
Term
| What was the worst treatment group of the vipeholm study? |
|
Definition
| The group that ate 24 toffees as SNACKS. No time to remineralize. So frequency of sugar intake is more important than amount of sugar |
|
|
Term
Which is not a weakness of the vipeholm study:
No microbial analysis
Hygeine not considered
starches not tested
different sugar sources not compared
liquid snacks not tested |
|
Definition
| different sugar sources not compared. They used sugar, toffee, and chocolate. Three sugar sources |
|
|
Term
Which two are acidogenic:
Sucrose
Mannitol
glucose
xylitol |
|
Definition
|
|
Term
| How do bacteria keep the acidity for long periods of time? |
|
Definition
| They first metabolize lots of the sugar making the environment acidic. They are also, at this time, storing lots of sugar in the form of intracellular polysaccharide. They will metabolize ICP later and continually secrete acid in this manner. |
|
|
Term
| How do we get the pH to normalize? |
|
Definition
| the saliva will decrease in its sugar concentration and increase argenine and urea, which will bacteria will metabolize and make ammonia, which is alkali |
|
|
Term
| At which percent of sugar does adding more become trivial in relation to acidity? |
|
Definition
| Once you hit 1% of sugar, the more you add, the pH won't change much at all. |
|
|
Term
2 part T/F
1. Sucrose, but not glucose, induce s mutans to make extra-cellular polysaccharide.
2. s mutans can make acid from sorbitol and mannitol |
|
Definition
|
|
Term
| What concentration of salivary MS indicates risk for caries? |
|
Definition
|
|
Term
| Why are some s mutans dangerous and others aren't? |
|
Definition
| Clonal variation. With sugary and acidic environment, s mutans slowly, genetically evolves to be more aciduric and acidogenic |
|
|
Term
| what is the envrionment lactobacilli like to colonize in? |
|
Definition
| They like colonizing in cavitations when the pH is around 5.0 |
|
|
Term
| Which are more aciduric and acidogenic, s mutans or lactobacilli |
|
Definition
| s mutans are more acidogenic, lactobacilli are more aciduric |
|
|
Term
Which species of lactobacilli would you not find in a microbial smear of a cavity?
casei
rhamnosus
brevis
fermentum |
|
Definition
| L brevis isn't in caries, but it is important in the pickling of foodstuffs |
|
|
Term
| Would you fine more s mutans or lactobacilli on the tongue? |
|
Definition
|
|
Term
| In a patient with 6 caries, you perform a tissue culture. Which species would have a higher concentration, s mutans or lactobacilli? |
|
Definition
| Lactobacilli are at higher concentrations that s mutans in patients with rampant caries |
|
|
Term
| T/F: In order to help high caries patiens, fluoride and chlorhexidine are used. Their primary purpose is to decrease lactobacilli species. |
|
Definition
| Although fluoride and chlorhexidie are used in high caries patients, their main role is to reduce s mutans, lactobacilli are largely resistant to them directly, but decreasing MS will indirectly reduce lactobacilli. |
|
|
Term
| If you eat lots of sugar, will MS expand or contract. |
|
Definition
| expand. The extra-cellular polysaccharide layers will become jelly-like |
|
|
Term
| How do multiple cells of s mutans bind at just one attachment site? |
|
Definition
| One will bind using an adhesin, then it will have polysaccharide on its surface. A second s mutans will bind to that polysaccharide. |
|
|
Term
|
Definition
| A mutan is an insoluble glucan (glucose polymer chain with alpha 1-3 links), S mutans has glucan binding sites that will bind to glucan chains. They also have glucosyl transferase which will make glucans from sucrose (fructose & glucose) |
|
|
Term
|
Definition
dextran (a 1-6): common, soluble
glycogen and starch (a 1-4)
cellulose beta (1-4): insoluble, prevalent in nature |
|
|
Term
What will glucans not do:
1 directly cause demineralization of the tooth
2 directly cause increase MS in plaque
3 indirectly cause gingivitis
4 directly decrease the amount of salivary buffer around the s mutans community |
|
Definition
| 1 directly cause demineralization of the tooth |
|
|
Term
Which has specific pathogens:
periodontitis or gingivitis? |
|
Definition
|
|
Term
What happens to
1 gingival margin
2 stippling
during gingivitis? |
|
Definition
gingival margin becoems hyperemic, blunted, or transparen.
stippling is lost |
|
|
Term
2 statement T/F
1 Gingivitis accompanies periodontitis.
2 Pure gingivitis (without perio) still has attachment at the CEJ. |
|
Definition
|
|
Term
| Why may probing depths be slightly longer than normal in gingivitis even when attachment levels haven't changed? |
|
Definition
| The PSEUDOPOCKET: gingiva hypertrophy causes high gingiva while having the same CEJ. So you have longer probing depths because of enlarged gingiva |
|
|
Term
| What are the results of gingivitis on gingival crevicular fluid? |
|
Definition
|
|
Term
| Define Necrotizing ulcerative gingivitis (NUG) |
|
Definition
| a gingival disease where microbes actively destroy gingival tissue causing interdental ulcerations. It is also called "trench mouth" |
|
|
Term
2 part:
Where does NUG usually happen?
What is the associated pseudomembrane composed of? |
|
Definition
| Lower anteriors, necrotizing tissue |
|
|
Term
| What type of microbes dominate the flora among those with NUG? |
|
Definition
| Spirochetes. Namely treponema denticola |
|
|
Term
| What is special about spirochetes and connective tissue? |
|
Definition
| Spirochetes will actually invade the connective tissue laterally, without changing attachment apically |
|
|
Term
| How long does NUG usually take place? |
|
Definition
| It is usually virus like in length. It lasts around 2 weeks and is self-limiting |
|
|
Term
| Which bacteria is found in increasing concentrations among those that are pregnant (2nd trimester especially)? |
|
Definition
| Prevotella intermedia. This causes increase in gingitis incidence. |
|
|
Term
| Why are pregnant women and youngsters in puberty more susceptible to gingivitis? |
|
Definition
| Because estradiol and testosterone stimulate growth in prevotella intermedia |
|
|
Term
| What are the effects of chronic periodontitis on endotoxin, gingival creveicular fluid flow, O2 levels, etc? |
|
Definition
|
|
Term
| What is the clinical crieteria for active periodontitis? |
|
Definition
| Attachement loss of over 2.5 mm in 2 months, or by measuring prostoglandins and arginases in gingival crevicular fluidby capillary insertion . |
|
|
Term
| What bacteria together form the RED COMPLEX? |
|
Definition
| Prevotella gingivalis, Treponema denticola, and Tannerella forsythia. These are all obligate anaerobes |
|
|
Term
What would be a more effective treatment of RED COMPLEX:
1 Decreasing concentration of prevotella by 99.9%
or
2 Decreasing Prevotella, treponema denticula, and Tannerella by 90% |
|
Definition
| 1 Decreasing concentration of prevotella by 99.9%. |
|
|
Term
What would be a more effective treatment of RED COMPLEX:
1 Decreasing concentration of prevotella by 99.9%
or
2 Decreasing Prevotella, treponema denticula, and Tannerella by 90% |
|
Definition
| 1 Decreasing concentration of prevotella by 99.9%. |
|
|
Term
| What are the two the function of Fusobactereum nucleatum for prevotella? |
|
Definition
| Fuso are obligate anaerobes and they progect Pg from oxygen and they detoxify H2O2 (much of which is made by strep species). It also gives Pg CO2 and ammonia (pH upper) |
|
|
Term
2 part T/F
1. A side effect of root planing is that it removes cementum
2. Removing contaminated cementum results in decreased conservancy of the gingival attachement. |
|
Definition
Both False.
You want to remove CONTAMINATED cementum during root planing. This removes the agent that has caused recession of gingival attachement. |
|
|
Term
2 part T/F
1. LPS is endotoxin with lipid A being the toxogenic part.
2. Gm + bacteria contribute to 15% of endotoxin related sepsis among IV drug users. |
|
Definition
1 True.
2 False- endotoxin is only in Gm - bacteria |
|
|
Term
| What happens to collagen during long-standing inflammation? |
|
Definition
| It decreases because of lysozomes secreted from PMNs. |
|
|
Term
2 statement T/F
1. Calculus is made up of lots of hydroxyapatite.
2. The surface area per square mm is small in calculus. |
|
Definition
1 True
2 False- surface area increases a great deal with calculus (think of a mountain range of hydroxyapatite crystals) |
|
|
Term
| Chimanzees with induced calculus (causing perio) and then after taking antibiotics the inflammation ceased. What did this teach us about calculus? |
|
Definition
| That it's main pathogenic feature isn't that it is an irritant, but that it fosters the growth of bacteria whith its increased surface area |
|
|
Term
| What do you expect would happen to these chimpanzees if you added calculus-loclaized pyrophosphates to their antibacterial regimen? |
|
Definition
| Not only would bacteria become extinct, but they would also have demineralized calculus. This would finally decrease their inflammation |
|
|
Term
| What environment best facilitates calculus growth? |
|
Definition
|
|
Term
| Which types of bacteria has "calculus seeds"? |
|
Definition
| Corynebacterium matruchotii (gm +) |
|
|
Term
| You increase salivary glycoproteins, pyrophosphate and Zn. What effect does this have on calculus growth? |
|
Definition
| It would inhibit the growth by competing for binding sites on calculus |
|
|
Term
2 part T/F
1. Proteases can facilitate calculus growth by stopping immunoglobins and glycoproteins from inhibiting crystalization.
2. Phosphoproteins and pyrophosphatases decrease crystal growth. |
|
Definition
1. True
2. False- these will cleave pyrophosphate, which is a potent calculus inhibitor |
|
|
Term
| What is the effect of fluoride on calculus growth? |
|
Definition
| Fluoride decreases activity of pyrophosphatases (calc-inhibitor) but also becomes incorporate in calculus as fluoro-hydroxyapatite (promoter). Its main function is as an inhibitor, though. |
|
|
Term
| What is the effect of s salivarius and increased urea in the saliva on calculus? |
|
Definition
| Increase in pH causing super-saturation and INCREASED calculus |
|
|
Term
| Is Rice is bad for caries and calculus? |
|
Definition
| yes. It has silicons, which promote crystal calculus |
|
|
Term
| Describe Aggresive perio. |
|
Definition
| It affects those <30, causes rapid attachment and bone loss, without substantial plaque accumulation or inflammation. Occurs most in females and non-caucasians, and is caused by Aggregatibacter actinomycetemcomitans (Aa) |
|
|
Term
| What is special about Aa in relation to the immune system? |
|
Definition
| It secrete leukotoxin, which kills mostly PMNs and monocytes. |
|
|
Term
| Which teeth are most afected by Aa? |
|
Definition
| Mostly molars and incisors, NOT premolars and canines |
|
|
Term
Arguments made for probing primary teeth mostly stem from concern over:
1 Chronic gingivitis
2 Chronic periodontitis
3 Aggressive periodontitis
4 Caries-associated bone loss |
|
Definition
| 3 Aggressive periodontitis |
|
|
Term
| What is refractory periodontitis? |
|
Definition
| perio caused by non-oral enteric species and rare oral species which are resistant and pop up due to the patients (usually elderly) systemic antibiotics |
|
|
Term
| Gingival ulcerations and distinctive, inflammatory band and increased candida are associated with patients with which systemic disease? |
|
Definition
|
|
Term
| What is the main way that perio causes systemic issues and which conditions has it been shown to associate with? |
|
Definition
| Mostly caused by perio related bacteria releasing inflammation causing endotoxin systemically. Can increase chances of pre-term birth, coronary heart disease, stroke, and diabetes. |
|
|
Term
|
Definition
| Created by MS, this is a bacteriocin that inhibits other strep species. |
|
|
Term
|
Definition
| A proteolytic enzyme that stops quorum sensing molecules among SM |
|
|
Term
| What is non-bacterial plaque? |
|
Definition
| This occurs when glucosyltransferase is released from SM and lodges in other oral surfaces like pellicle and continues making glucan. |
|
|
Term
| What is the stephan curve? |
|
Definition
| It is a curve comparing pH over time given different sugar en vivo. |
|
|
Term
Which isn't a predisposing factor to chronic periodontitis according to the notes?
1 tobacco smoking
2 emotional stress
3 high lipid diet
4 compromised health
5 alcoholism |
|
Definition
|
|
