MCQs on Dental caries Part 3

# Streptococcus mutans is considered to be a principal etiologic agent of caries because it produces acid and it:
A. forms a gelatinous matrix
B. metabolizes substrate from saliva
C. derives energy from enamel constituents
D. lives symbiotically with lactobacillus

# Miller put forth the acidogenic theory of dental caries in the year:
A. 1890
B. 1920
C. 1924
D. 1980

# 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 amylopectins
C. be lethal for gnotobiotic animals
D. produce intracellular dextrans

# Initiation of dental caries depends upon:
A. formation of large amount of acid
B. availability of carbohydrate food
C. viscosity of saliva
D. Localisation of acid over tooth surface

# Caries, all are true except:
A. Lactobacillus is the main causative organism in plaque
B. Smooth surface caries occur due to streptococcus mutans
C. Pit and fisssure caries can be prevented by using pit and fissure sealants
D. Fluorides help in reducing caries incidence

# The enzyme glucosyl transferase secreted by Streptococcus mutans synthesizes glucans from:
A. Glucose
B. Fructose
C. Sucrose
D. Lactose

# The lateral spread of dental caries is facilitated mostly by the :
A. Enamel spindles
B. Dentinoenamel junction
C. Enamel lamellae
D. Striae of Retzius

# The probable reasons for a high incidence of dental caries in the teenage population relates most directly to:
A. Rapid growth
B. Frequency of sucrose intake
C. Negligence in visiting the dentist
D. Carelessness in oral hygiene habits

# In a caries free individual, the saliva has:
A. low buffering capacity for acids
B. medium buiffering capacity for acids
C. High buffering capacity for acids
D. Buffering capacity of saliva is independent of caries incidence

# Early invading bacteria in carious lesions are called:
A. Microcosm
B. Pioneer bacteria
C. Advancing bacteria
D. Anaerobic bacteria