Ability to prepare dental cavity

Some of the following statements about gnarled enamel are true: It occurs near the cervical regions and the incisal and occlusal areas. It is formed when groups of enamel rods entwine with adjacent groups of rods. It is subject to fracture more than regular enamel. It is a structureless layer of enamel. It is considered growth rings.

Secondary dentin has the following features, except: it is usually completed 3 years after tooth eruption (for permanent teeth). in multirooted teeth it tends to be thicker on the roof and floor of the pulp chamber. surrounds the dentinal tubules, forming the walls of the tubuls. the tubular fluid flow is restricted. comprises the main body of dentin, being located between the tubules.

Transparent dentin has the following characteristics, except: it is produced during more severe injury, which causes the death of primary odontoblasts. it is produced by the physical occlusion of the tubule lumens by means of the precipitation of minerals. The secondary odontoblasts generate transparent dentin. it has increased transparency. it is usually atubular in structure.

About reparative tertiary dentin, we can say that: it is usually atubular. it is generated by the secondary odontoblasts. it appears as a localised dentin deposit on the wall of the pulp cavity immediately subjacent to the area on the tooth that received the injury. it is generated by remineralization of the intertubular dentin. it is tubular in nature and continuous with primary and secondary dentin.

Cementum has the following features: Cementum is not capable of repairing itself. Cementum is formed by cells known as odontoblasts. The cementum is yellow. The cementum is slightly lighter in color than dentin. in case of excessive orthodontic pressures, cementum will repair itself.

#The enamel rods have the following characteristics, except: the diameter near the dentinal borders is smaller than the diameter near the surface. in transverse section, enamel rods have a rounded head portion and a tail portion. Enamel rods follow a wavy, spiraling course. in the cervical region of permanent teeth, they are oriented outward in a slightly apical direction. the diameter near the dentinal borders is larger than the diameter near the surface.

# Structurally, enamel is composed of the following elements, except: enamel rods. rod sheaths. tubules. cementing inter-rod substance. enamel prisms.

Dentin has the following characteristics: it is significantly softer than cementum. It is normally yellow-white and slightly darker than enamel. it is flexible. Dentin surfaces are more opaque, being less reflective to light than similar enamel surfaces. Dentin flexibility doesn’t help support the more brittle, less resilient enamel.

# One of the statements related to cementum is false: Cementum is capable of repairing itself. Cementum keeps the attachment of periodontal fibers intact. cementum is flexible. Two kinds of cementum are formed: acellular and cellular. Cementum is formed continuously throughout life.

The dentin tubules have the following characteristics, except: are small canals that extend across the entire width of dentin. Each tubule contains the cytoplasmic cell process (Tomes fiber) of an odontoblast. The lumen of the tubules has a constant diameter. Each dentinal tubule is lined with a layer of intertubular dentin. Near the DEJ the tubules are divided into several branches.

#The dentinal fluid has the following features, except: there is an increased tubular fluid movement toward the pulp when enamel and cementum are removed. contains water, matrix-proteins, matrix-modified proteins and mineral ions. flows from the pulp toward the external surface of the tooth. there is an increased tubular fluid movement toward the cut surface when enamel and cementum are removed. the movement of dentinal fluid is involved in dentin sensitivity.

The cementodentinal junction has the following features, except: has crest of the waves penetrating toward the dentin. is a relatively smooth area in the permanent tooth. is a wavy line. is very durable. the collagen fibers from dentin continue with those from cementum.

The structures of enamel that may play a role in the spread of dental caries are: enamel tufts. enamel spindles. enamel lamellae. prismless enamel. gnarled enamel.

Pulp cavity size varies: with tooth size in the same person. among individuals. with the thickness of predentin. with age. with the thickness of odontoblasts layer.

Predentin has the following features: it is the first layer of dentin. it is found immediately next to the cell bodies of the odontoblasts. it is a mineralized zone of dentin. it is found always on the pulpal surface. it is found always on the pulpal surface.