(A) Zone of sclerosis, backterial invasion, decalcification zone
(B) Bacterial invasion, decalcification zone, zone of sclerosis
(C) Zone of sclerosis, decalcification zone, bacterial invasion
(D) Decalcification zone, zone of scierosis, backterial invasion

(A) Dextran
(B) Sucrose
(C) Glucose
(D) Polysaccharide

(A) 4.9-5.1
(B) 5.2-5.5
(C) 4.3-4.5
(D) 3.5-4.5

(A) Organic matrix
(B) Interprismatic substance
(C) Enamel cuticle
(D) Enamel lamellae

(A) Raw starch
(B) Sucrose
(C) Cooked starch
(D) Fructose

(A) Zone which can not be remineralized
(B) Zone of bacterial invasion
(C) Zone in which collagen is irreversibly denatured
(D) Zone that need not be removed before restoration

(A) 1890
(B) 1924
(C) 1920
(D) 1980

(A) Availability of carbohydrate food
(B) Formation of large amount of acid
(C) Viscosity of saliva
(D) Localization of acid over tooth surface

(A) Lactobacillus is main acusative organism in plaque
(B) Fluorides help in reducing caries incidence
(C) Pit and Fissure caries can be prevented by using pit and tissue sealants
(D) Smooth surface caries occur due to streptococcus mutans

(A) Enamel lamellae
(B) Dentinoenamel junction
(C) Enamel spindles
(D) Striae of Retzius