Oral And Dental Infections Flashcards
(35 cards)
Are oral bacterial infections usually monomicrobial or polymicrobial?
Polymicrobial
What are dental caries?
Localized destruction of the tenth due to acids produced during bacterial fermentation of carbohydrates
Acidic production in the mouth causes:
- lower pH
- ecological shift from S. Oralis/Sanguis species (normal) -> MS. Lactobacilli (abnormal)
- demineralization of teeth
Dental caries epidemiology
Most prevalent chronic disease of childhood
High dental caries rates are associated with:
- increased carbohydrate consumption
- low socio -economic status
- meth use
- developing nations
“Meth Mouth”
Meth use causes all of the following:
1) xerostomia (dry mouth)
- this is bad since saliva has natural antibacterial properties and buffers acid production
2) clenching/grinding of teeth
- bad since it wear enamel down
3) low overall oral hygiene
4) cravings for high carbohydrate/sugar foods and beverages
“Baby bottle tooth decay”
Front teeth caries seen in childhood due to repeated ingestion of sweetened liquids
What are the 4 main factors in development in caries?
Plaque microorganisms
Host factors present:
- teeth
- saliva (antimicrobial properties and possess large amounts of Ca and P ions = remineralization)
- oral hygiene
Time
Diet (amount of carbohydrates)
Streptococcus mutans
Is part of normal oral flora
Gram (+) cocci bacteria that induces lactic acid fermentation in the presence of high carb diets
- decreases pH and initiates dental caries
- does this via glucosyltransferase*
- turns sucrose into glucan molecules which stick to teeth
Lactobacillus
super small part of normal flora, higher numbers is either pathogenic or in response to an already low pH environment
Gram (+) bacilli bacteria that induces lactic acid fermentation in the presence of high carb diets
- decreases pH and initiates dental caries
- also further progresses caries formation after initiating of streptococcus mutans
Actinomycosis Viscosus
Is not a part of the normal mouth flora
Gram (+) bacilli that has an unknown role, but is known to function in root surface caries
- needs caries to be formed already to colonize
Veillonella species
Normal oral flora that combats caries production
Gram (-) cocci that is anaerobic and in the presence of lactate, produces weaker acids to raise the pH in the mouth
- elevated pH kills other bacterial species that forms caries
What is the most cariogenic sugar?
Sucrose
- is the prime substrate in lactic acid fermentation
in dental carries used by S. Mutans to form glucan’s which are used for adherence
Diagnosis of caries
White spot on tooth enamel = early
Fissure lesions often appear brown
Root lesions appear leathery
Cavitation viewed by eye (if severe) or by light-induced fluorescence
Use of probe = soft on texture with (+/-) tenderness
What two cariogenic bacteria are most closely tied to caries activity based on amount?
strep mutans and lactobacillus species
High = >10^6 mutans and >10^5 lactobacillus
Low = <10^5 mutans and <10^4 lactobacillus
Treatments of dental caries
1) removal of lesions and followed up by replacement with restoration material
- fillings/sealants/etc
2) use of remineralization agents
What is fluoride’s action in prevention of dental caries?
Makes minerals of the teeth less soluble in acid
- flurosis = excessive exposure to fluoride while permanent teeth are developing
- looks like a white stripe along edges of teeth
- is usually benign and is a cosmetic issue*
How does normal flora in mouth shift from healthy -> periodontitis?
Healthy:
- (+) cocci and rods dominant
- facultative organisms dominant
Gingivitis:
- (+) cocci and rods are equal to negative rods
- facultative organisms dominant
Periodontitis:
- (-) rods are dominant
- anaerobic organisms dominant
increases in actinomycetes, capnocytophaga and anaerobic organisms increase in gingivitis
increases in Porphyromonas gingivalis and prevotella intermedia and anaerobic organisms in periodontitis
Chronic gingivitis
Inflammatory response limited to marginal gingiva without bone loss of deep periodontal pockets
- is reversible with good oral hygiene and removal of plaque/calculus
Common signs/symptoms:
- red swollen gingiva
- bleeding gums
- halitosis
Periodontitis
- predominant cause of tooth loss in adults*
- gets worse with age
Progression of gingivitis which includes:
- loss of collagen attached to tooth and bone
- loss of bone
- deep periodontal pockets
spreading of plaque causes periodontal pocket formation -> increases anaerobic environment and increased replication of anaerobic organisms
Signs/symptoms:
- inflamed gingiva
- gingival recession
- bleeding pockets
- tooth mobility/migration
- bone loss around teeth
- halitosis
What is the primary organisms responsible for chronic periodontitis?
Porphyromonas gingivalis
- normal flora opportunistic bacterium that only thrives in acidic environments (stays in check until caries form)
- is asaccharolytic: can use sugars as fuel but can also use amino acids and lipids*
Is a BLACK PIGMENTED anaerobic gram (-) coccobacilli
- virulence factors = fimbriae, hemagglutinins, hemolysis, proteases, K antigens (capsule)
Other chronic periodontitis species
Prevotella intermedia
Tannerella forsythia
these two can only use saccharides as fuel sources (saccharolytic)
Capnocytophaga
- Gram (-) bacilli that is fusiform/spindle shape and has gliding motility
- is a facultative anaerobe and capnophilic
- *is associated only with aggressive periodontitis**
Treatment of chronic periodontitis
Mechanical therapies
- removal of plaque and inflamed tissues
- replacement of lost teeth
Oral hygiene improvements
Antimicrobial agents
- mouthwashes
- antibiotics (tetracycline/doxycycline (#1)/metronidazole)
Aggressive periodontitis epidemiology
Rare with possible genetic links (unknown for sure thou)
- occurs in younger adults
- more common in Asians and west Africans
- more common in females
- associated with immune deficiencies
currently tetracycline is the most effective
Acute necrotizing ulcerations gingivitis (ANUG)
Is very aggressive periodontitis
Epidemiology:
- poor oral hygiene
- malnutrition
- heavy smoking
- emotional stress
- recent infections
Sings/symptoms:
- gingiva are red, inflamed, shiny, and bleeding with ulcers
- lesions are painful with pseudomembrane
- metallic taste in mouth with halitosis
- NO fever/malaise or lymphadenopathy
Treatment:
- removal of plaque and local debridement
- improve oral hygiene
- tetracycline antibiotics
What organisms are predominant in ANUG?
Fusobacterium nucleatum
- gram (-) bacilli
- normal flora obligated anaerobic that is in check until acidic conditions
Treponema vincentii; denticola
- gram (-) spirochete
- obligate anaerobe
