Oral Microbiology Preparation (Dr. Chhay Sokdalis)

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402

1 / 80

1) Which of the following statements on clinical sign of dental caries is INEXACTE?

a. Chalkywhite lesion

b. Roughened and cavitation

c. Pseudomembrane (slough)

d. White-spot lesion.

2 / 80

2) Lysozyme is present in?

a. Sweat

b. Cerebro spinal fluid (CSF)

c. Saliva.

d. Urine

3 / 80

3) Bacterial pathogens attach most often by all except which of the following mechanisms?

a. Fimbriae (pili)

b. Adhesins

c. Glycocalyx.

d. Spikes

4 / 80

4) The dietary carbohydrate most likely involved in etiology of dental caries is 😕

a. Sucrose

b. Polysaccharide

c. Dextran

d. Xylitol.

5 / 80

5) How to manage dental caries?

a. Eliminate primary source of infection

b. Initial local debridement with ultrasonic scaling

c. Minimal cavity preparation techniques

d. Institute surgical drainage.

6 / 80

6) Which of the following statements on dentoalveolar abscess is true?

a. it is a infection of sublingual and submandibular spaces

b. it is often precipitated by bacteria from the systemic route (anachoresis)

c. it often resolves without antibiotics after adequate drainage.

d. it is frequently implicated as a cause of brain abscess

7 / 80

7) With regard to prevention of dental caries, which of the following statements are true?

a. water fluoridation, though effective, leads to other major systemic illnesses

b. probiotic therapy with ‘cariogenic’ bacteria is the most promising approach

c. substituting cariogenic artificial sweeteners

d. remineralization of early lesions can be accomplished by fluoridated toothpaste.

8 / 80

8) Predisposing factors for acute necrotizing ulcerative gingivitis include INEXACT:?

a. heavy smoking

b. immunodeficiency

c. severe malnutrition

d. diabetes.

9 / 80

9) Virus replicate by which of the following?

a. Reproduction.

b. Within a host cell

c. Extracellular

d. Cell division

10 / 80

10) Communicable diseases can spread by several methods. Which is not an example of the direct transmission mode of disease spread?

a. Contact with contaminated food

b. Transfusion

c. Placental transfer.

d. Sexual intercourse

11 / 80

11) Which of the following statements on clinical sign of necrotizing ulcerative gingivitis is INEXACTE?

a. Loss of supporting tissues (noma).

b. Inflamed, red, shiny and bleeding gingivae

c. Unpleasant metallic taste

d. Irregular alveolar bone loss around teeth

12 / 80

12) Which of the following statements on periodontal disease is INEXACT?

a. Manage by restoration

b. One of major diseases afflicting humankind

c. Disorders of supporting structures of teeth

d. Can be controlled by using mechanical cleansing techniques.

13 / 80

13) Which of the following statements on streptococci are not true?

a. mutans group streptococci cause caries

b. Can be primarily differentiated by their hemolytic reactions on blood agar

c. Can cause caries in the absence of sucrose

d. Some are Gram-positive and anaerobic

14 / 80

14) An example of a nonspecific chemical barrier to infection is…?

a. unbroken skin

b. cilia in the respiratory tract

c. cytotoxic T cells.

d. lysozyme in saliva

15 / 80

15) The main difference in true bacteria and mycoplasma is that it does not posses:?

a. ATP synthesis

b. A capsule.

c. Flagella

d. Cell wall

16 / 80

16) The main causative agent of Ludwig angina is:?

a. Staphylococci

b. Streptococcus pneumonia

c. Treponema pallidum

d. Fusobacteria.

17 / 80

17) Mouthwashes contain several chemical agents to effectively control oral malodor. Select the agent that does not belong in mouthwashes:?

a. Cetylpyridinium.

b. essential oils

c. alcohol

d. Chlorhexidine gluconate

18 / 80

18) True about caries, all EXCEPT:?

a. Demineralization of enamel.

b. Microorganisms play the most essential role

c. Not due to microorganisms

d. Chronic endogenous infection

19 / 80

19) Caries, all are true except:?

a. Smooth surface caries occur due to streptococcus mutans

b. Lactobacillus is the main causative organism in plaque

c. Fluorides help in reducing caries incidence.

d. Pit and fisssure caries can be prevented by using pit and fissure sealants

20 / 80

20) Which of the following statements on complication of Ludwig’s angina is INEXACTE?

a. Airway obstruction due to edema of glottis

b. pread of infection to masticator

c. Death due to asphyxiation

d. Respiratory tract infections.

21 / 80

21) Which of the following is associated with dental caries?

a. Staphylococcus aureus.

b. Streptococcus mutans

c. Streptococcus pneumonia

d. Lactococcus lactis

22 / 80

22) The main causative agent of Ludwig’s angina is:?

a. Legionella infection

b. Staphylococci

c. Group A streptococci.

d. Porphyromonas

23 / 80

23) Which of the following statements on acute necrotizing ulcerative gingivitis is INEXACTE?

a. Commonly associated with poor and neglected oral hygiene

b. If untreated, ulcers enlarge and spread to involve marginal

c. The disease may be inherited (autosomal recessive).

d. Possibly systemic diseases

24 / 80

24) Microorganisms play the most essential role.?

a. Streptococcus anginosus.

b. Streptococcus mutans

c. Streptococcus agalactiae

d. Streptococcus bovis

e. Dental caries is associated with:

25 / 80

25) Which of the following vaccines would you recommend to your new female dental surgery assistant starting work with you?

a. Hepatitis A

b. Hepatitis B immunoglobulin

c. Hepatitis C.

d. Measles–mumps–rubella (MMR)

26 / 80

26) Which of the following statements on prevention of dental caries is INEXACTE?

a. Plaque-free by routine oral hygiene measures.

b. Probiotics replacement of cariogenic bacteria

c. Increasing cariogenic flora

d. Stopping or reducing between-meal consumption of carbohydrates

27 / 80

27) Dentoalveolar abscess is treated by:?

a. Periodontal flap procedure

b. Gingivectomy

c. Gingivoplasty

d. Drainage through the gingival sulcus or by an external incision.

28 / 80

28) The legend of worms, endogenous theories, chemical theories and parasitic theory are early theories explaining:?

a. Periodontitis

b. Osteomylitis.

c. Dental caries

d. Gingivitis

29 / 80

29) Microorganism that can grow in the presence as well as in the absence of molecular oxygen is?

a. obligatory aerobic

b. microaerobically

c. facultatively anaerobic.

d. obligatory anaerobic

30 / 80

30) An abortive infection is one in which: ?

a. Cell multiplication is stopped.

b. Progeny virus is not produced

c. The infected cells are killed

d. Transplacental infection of the fetus occurs

31 / 80

31) Members of the genus Lactobacillus are normal microflora of the?

a. Skin

b. Hair

c. Nasopharynx.

d. Mouth

32 / 80

32) Which of the following procedures can be regarded as optimal for controlling cross infection in a dental clinic?

a. Wearing gloves after removal of all hand jewellery.

b. Wearing a single face mask for 3 h

c. Wearing headgear for all operational procedures

d. Washing the gloves and reusing after visual examination of a patient

33 / 80

33) The most common protozoa in the oral cavity of people ?

a. Trichomonas tenax

b. Entamoeba histolytica

c. Giardia muris

d. Giardia lamblia.

34 / 80

34) Which of the following statements on the natural history of periodontal disease is INEXACT?

a. facultative anaerobes predominate in gingivitis.

b. Gram-negative anaerobes predominate in chronic periodontitis

c. the proportion of Gram positive rods decreases to nearly 5% in chronic marginal gingivitis

d. Gram-positive cocci predominate in healthy gingival crevice

35 / 80

35) Which of the following statements on chronic periodontitis is INEXACTE?

a. Most prevalent disease globally

b. 95% of all periodontal diseases.

c. Prevalence and severity decrease with age

d. Morbidity 70–80%

36 / 80

36) Which of the following statements on clinical sign of chronic periodontitis is INEXACTE?

a. Gross gingival inflammation, fibrosis and some shrinkage

b. Irregular alveolar bone loss around teeth

c. Inflamed, red, shiny and bleeding gingivae.

d. Tooth mobility and migration

37 / 80

37) The bacteria detected in localized aggressive periodontitis are:?

a. Treponema denticola and fusobacterium nucleatum.

b. Fusiformis and Tanerella forsythus.

c. A. actinomycetemcomitans, Capnocytophaga spp. and Porphyromonas gingivalis.

d. Borrelia vincenti and medium size spirochetes.

38 / 80

38) Mouthwashes used for controlling oral malodor should contain?

a. Antibacterial agent

b. Sugar to make them more palatable to consumers

c. Xylitol.

d. Alcohol

39 / 80

39) The mutans group of streptococci are key cariogenic pathogens. Which of the following belongs to the mutans group?

a. Streptococcus pyogenes

b. Streptococcus mutans

c. Streptococcus pneumonia.

d. Streptococcus saprophyticus

40 / 80

40) Which of the following statements on dental caries are true?

a. approximately 90% of people over 60 years in the West have root surface caries

b. fissure caries is commonly seen in the lingual surface of the incisors

c. recurrent caries is commonly associated with an existing restoration.

d. signs of fissure caries can be first detected in dentine

41 / 80

41) Which of the following bacteria that is predominant in chronic periodontitis?

a. Porphyromonas gingivalis

b. Prevotella intermedia.

c. Actinomyces viscsus

d. Streptococcus sanguinis

42 / 80

42) What are the predominant plaque bacteria in periodontitis?

a. Anaerobic rods (+)

b. Anaerobic rods (-).

c. Facultative anaerobia cocci (+)

d. Facultative anaerobia cocci (-)

43 / 80

43) Widely accepted theory of dental caries is 😕

a. Autoimmune theory.

b. Acidogenic theory

c. Proteolytic theory

d. Proteolytic chelation theory

44 / 80

44) The organisms which can grow best in the presence of a low concentration of oxygen?

a. Anaerobic.

b. Aerophilic

c. Microaerophilic

d. Aerobic

45 / 80

45) Probiotics exhibit all BUT the following characteristics:?

a. Remain viable for a long time

b. Mimic antibiotics

c. Have beneficial effect on host.

d. Nontoxic and nonpathogenic to host

46 / 80

46) Demineralization of inorganic portion and destruction of organic of tooth is known as:?

a. Dentinal caries

b. Enamel caries

c. Pulpitis.

d. Dental caries

47 / 80

47) Which genus of bacterium contributes to plaque, caries, gingivitis, and periodontal disease?

a. Staphylococcus

b. Bacillus.

c. Streptococcus

d. Escherichia

48 / 80

48) What are the predominant plaque bacteria in gingivitis?

a. Facultative anaerobia cocci (-) and Anaerobic rods (-)

b. Facultative anaerobia cocci (+) and Anaerobic rods (-)

c. Anaerobic cocci (-) and Facultative anaerobia rods (-).

d. Anaerobic cocci (+) and Facultative anaerobia cocci rods (+)

49 / 80

49) Which of the following statements on diagnosis of dental caries is INEXACTE?

a. Probing

b. Organoleptic assessment.

c. Laser fluorescence

d. Electrical impedance

50 / 80

50) Aggressive periodontitis is treated by:?

a. Amoxicillin 500 mg 3 times/day for 2 weeks.

b. Tetracycline 250 mg 3 times/day for 4 weeks

c. Metronidazole 250 mg 3 times/day for 1 weeks

d. Penicillin 500 mg 3 times/day for 3 weeks

51 / 80

51) The human body provides a favorable habitat for microorganisms. Which of the following does not contribute to this favorable habitat?

a. Low levels of moisture

b. Constant source of nourishment

c. Relatively stable pH.

d. Stable temperature

52 / 80

52) How to manage acute necrotizing ulcerative gingivitis?

a. Institute surgical drainage.

b. Reducing cariogenic flora

c. Initial local debridement by ultrasonic scaling

d. Tetracycline 250 mg 3 times/day for 4 weeks

53 / 80

53) For a bacterium to be seriously considered in the etiology of dental caries, it must 😕

a. exist regularly in the dental plaque

b. produce extracellular proteolytic enzyme

c. be lethal for animals

d. produce intracellular dextrans.

54 / 80

54) The peak incidence of juvenile periodontitis in children occurs at ages:?

a. 5-7 years

b. 10-13 years.

c. 1-3 years

d. Birth-6 months

55 / 80

55) Viruses that persist in the cell and cause recurrent disease are considered?

a. latent

b. resistant.

c. oncogenic

d. cytopathic

56 / 80

56) Normal flora help protect the body from pathogens … ?

a. by sharing plasmids with pathogenic bacteria

b. by competing with other bacteria

c. by secreting histamines.

d. by attacking pathogenic bacteria

57 / 80

57) Which of the following statements on aggressive periodontitis is EXACTE?

a. 95% of all periodontal diseases.

b. Initiation is onset of puberty

c. Most prevalent disease globally

d. Prevalence and severity decrease with age

58 / 80

58) Which of the following bacteria that is predominant in healthy condition?

a. Actinomyces viscsus

b. Actinomyces israelii.

c. Streptococcus sanguinis

d. Streptococcus milleri

59 / 80

59) Microorganisms that are frequently implicated in the pathogenesis of periodontal abscess include:?

a. Staphylococci

b. Porphyromonas spp.

c. Treponema pallidum

d. Streptococcus pneumonia

60 / 80

60) The primary cause of periodontal diseases is?

a. Calculus

b. Restoration.

c. Malocclusion

d. Dental Plaque

61 / 80

61) How to manage dentoalveolar abscess?

a. Removing source of infection and prescribing antibiotics

b. Initial local debridement.

c. Reducing cariogenic flora

d. Probiotics replacement of cariogenic bacteria

62 / 80

62) Which of the following disease most commonly afflicts human?

a. Periodontal disease

b. Dentoalveolar abscess

c. Ludwig’s angina

d. Periodontal abscess.

63 / 80

63) The following infectious agents are likely to be transmitted in dental care settings:?

a. Candida albicans

b. Streptococcus pyogenes

c. Ph. Heng Kanika

d. Hepatitis G

e. Influenza.

64 / 80

64) A facultative anaerobic is:?

a. Ordinarily an aerobe but can grow in absence of O2.

b. Only grow anaerobically

c. Only grow in the presence of O2

d. Ordinarily an anaerobe but can grow with O2

65 / 80

65) Gram staining reflects in bacteria?

a. differences in bacterial metabolism

b. presence or absence of nucleus.

c. differences in the bacterial plasmatic membrane

d. differences in the cell wall structure

66 / 80

66) What is the cause of death in Ludwig angina?

a. Asphyxia

b. Dysrhythmia

c. Pneumonia

d. Wall rupture.

67 / 80

67) Initiation of dental caries depends upon:?

a. viscosity of saliva

b. formation of large amount of acid

c. availability of carbohydrate food

d. Localisation of acid over tooth surface.

68 / 80

68) Following can be used for cultivation of viruses EXCEPT:?

a. Diploid cell line

b. Primary cell

c. Blood agar.

d. Cell cultures

69 / 80

69) Which of the following statements on dentoalveolar infections is INEXACTE?

a. Pus-producing infections associated with teeth and surrounding supporting structures

b. Endogenous oral commensals, usually from apex of a necrotic tooth

c. Clinical presentation depends on virulence of causative microorganisms.

d. Prevalence and severity increase with age

70 / 80

70) Turbid dentin in carious tooth is all EXCEPT:?

a. Zone that need not be removed before restoration.

b. Zone of bacterial invasion

c. Zone in which collagen is irreversibly denatured

d. Zone which cannot be remineralised

71 / 80

71) Which is not true about Ludwig angina?

a. May need emergency tracheostomy

b. Involves submandibular space

c. Caused by an acute or chronic destructive process in periodontium

d. Maintain fluid balance.

72 / 80

72) In dentoalveolar abscess, the bacteria reach pulp by:?

a. Poor oral hygiene

b. Primary herpetic gingivostomatitis.

c. Plaque microorganisms

d. Traumatic exposure during dental treatment

73 / 80

73) What are the predominant plaque bacteria in healthy condition?

a. Anaerobic cocci (-) and rods (-).

b. Facultative anaerobia cocci (-) and rods (-)

c. Facultative anaerobia cocci (+) and rods (+)

d. Anaerobic cocci (+) and rods (+)

74 / 80

74) Which of the following statements on Ludwig’s angina is INEXACTE?

a. it may warrant an urgent tracheostomy

b. little amount of pus is yielded on surgical drainage.

c. it needs to be treated with high-dose, parenteral metronidazole and penicillin

d. the majority of cases are due to submandibular sialadenitis

75 / 80

75) Viruses can be cultivated in?

a. Lab media

b. Tissue culture

c. Broth

d. Blood culture.

76 / 80

76) Which of the following bacteria that is predominant in aggressive periodontitis?

a. Porphyromonas gingivalis

b. Prevotella intermedia.

c. Aggregatibacter actinomycetemcomitans

d. Streptococcus sanguinis

77 / 80

77) Which of the following statements on dental caries is INEXACTE?

a. Chronic endogenous infection caused by normal oral commensal flora

b. Destruction of tissues of tooth by bacterial fermentation of dietary carbohydrates.

c. Commonly associated with malnutrition and possibly systemic diseases

d. Carious lesion is result of demineralization of enamel

78 / 80

78) Main predisposing factors of acute necrotizing ulcerative gingivitis is:?

a. Host factors

b. Intake of fermentable carbohydrates.

c. Dental caries

d. Severe malnutrition

79 / 80

79) There are many different types of bacteria normally present in the oral cavity. Which of the following is the name of the one most likely to be associated with the onset of dental caries?

a. Staphylococcus

b. Streptococcus.

c. Spirochaetes

d. Bacteroides

80 / 80

80) Chronic periodontitis is characterized by INEXACT:?

a. systemic symptoms like fever

b. gingival recession

c. tooth mobility and migration

d. absence of pain in general.

Your score is

The average score is 86%

Any comments?