Microbes in Dental Disease Flashcards
What bacteria is indicated in caries?
Streptococcus Mutans
What virulence factor does Strep mutans have?
Glycolytic systems
EPS/sucrose metabolism
Very acidic
Attachment mechanisms- GTF, Ag
Ecological competitiveness at low pH
Describe caries progression in terms of biofilm formation.
Adhesion of bacteria
Survival and growth
Biofilm formation
Complex plaque
Acid
Caries
What clinical specimen would you take if there was caries?
Specimen from occlusal surface swab.
What methods could be used to detect the organism present?
PCR
Cell culture
DNA probes
NGS
What bacteria is present in Periodontitis?
Porphyromonas Gingivalis- strict anaerobe
Prevotella Intermedia
Tannerrella Forsythia
Treponema Denticola
What bacteria is present in Gingivalis?
Prevotella Intermedia
Fusobacterium Nucleatum
Actinomyces
Describe the development of a plaque biofilm.
Adhesion
Colonisation
Accumulation
Complex community- nutrients can be shared, difficult to remove now
Dispersal
What are the virulence factors of P.Gingivalis?
Fimbriae- help invade membrane vesicles of host cells by binding to cellular integrals
Endotoxin- LPS
Proteases
Capsular polysaccharide and outer membrane vesicles
Gingipains
If you wanted to try determine the bacteria present in perio disease of a patient, what would you do?
Take a sample of plaque from the gingival margin and subgingivally of the worst site- use a paper point.
What are the 4 types of oral candidiasis?
Pseudomembranous- thrush
- can be rubbed off.
Erythematous- atrophic, denture related
Hyperplastic- candidal leukoplakia
- looks like lichen planus.
- The hyphae invade the tissues and grow inside- cannot be wiped off.
Angular Cheilitis- hyphae interact with gram positive bacteria.
What treatment would be used for Angular Cheilitis?
Topical miconazole cream- 2% 20g tube- apply to angles of the mouth twice a day.
If someone cannot use miconazole
- Prescribe sodium Fusidate ointment 2%, 15g tube, apply to angles of the mouth 4 times a day.
Why might someone get a candida infection?
Immunocompromised- chemotherapy, radiotherapy, HIV, diabetes
Steroid inhaler
Poor denture hygiene
Patients with nutritional deficiency
What treatment is advised for pseudomembranous candidiasis?
Local measures first- OHI, if taking corticosteroid inhaler then rinse mouth out after using it, Chlorhexidine mouthwash 0.2%.
Fluconazole capsules 50mg- 1 capsule per day for 7 days.
or
Nystatin- oral suspension 100,000 units/ml.
Describe Newton’s classification of denture stomatitis.
Type 1- localised inflammation
Type 2- Diffuse inflammation
Type 3- Granular inflammation
What fungal species are responsible for candida infections?
Candida albicans- sensitive to fluconazole and miconazole
Candida Glabrata- not sensitive to azaleas.
- Must use Nystatin instead.
Describe the pathogenesis of Candida.
Adhesion
Colonisation
Hyphal penetration and invasion
Vascular dissemination
Endothelial colonisation and penetration
How do Azoles work?
Inhibit the synthesis pathway so ergosterol isn’t synthesised.
How do polyenes work?
Bind directly to ergosterol and make pores in it so that the cell contents leak out and cause the fungus to die.
What types of bacteria are present in primary and secondary endodontic lesions?
Primary infection- gram negative bacilli
Secondary infection- E.Faecalis
