1.
Dentin and pulp cannot be seen clinically unless the teeth & associated periodontium are unhealthy.
Correct Answer
A. True
Explanation
The statement is true because dentin and pulp, which are the inner layers of the tooth, are not visible clinically unless there is some form of dental disease or damage. In a healthy tooth, the outer layer of enamel covers and protects the dentin and pulp, making them invisible to the naked eye. However, when there is tooth decay, gum disease, or other dental issues, the enamel may become compromised, allowing the dentin and pulp to be exposed or affected. Therefore, in normal circumstances, dentin and pulp cannot be seen clinically unless there is an underlying dental problem.
2.
What layer of the tooth makes up the bulk of teeth?
Correct Answer
Dentin
Explanation
& IT PROTECTS THE PULP
3.
What basic color is dentin mainly?
Correct Answer
Yellow
Explanation
Dentin is mainly a yellowish color. It is the hard substance that makes up the majority of a tooth and lies beneath the enamel. Dentin is responsible for giving teeth their natural color, which can range from yellow to grayish-white. The color of dentin can become more visible if the enamel wears down or becomes thinner, resulting in a more yellow appearance of the tooth.
4.
Dentin cannot be removed
Correct Answer
B. False
Explanation
Healthy dentin can be removed by hand instrumentation
5.
Enamel appears more _________ than dentin
Correct Answer
A. Radiopaque
Explanation
Enamel appears more radiopaque than dentin because it is denser and contains less organic material. Radiopaque substances appear white on a radiograph because they absorb more X-rays, while radiolucent substances appear darker because they allow more X-rays to pass through. Enamel, being a harder and denser material, absorbs more X-rays and appears more radiopaque compared to dentin.
6.
The process of dentin matrix formation
Correct Answer
Dentinogenesis
Explanation
Dentinogenesis refers to the process of dentin matrix formation. Dentin is a hard, calcified tissue that forms the bulk of the tooth structure. During dentinogenesis, specialized cells called odontoblasts secrete an organic matrix that eventually mineralizes to form dentin. This process occurs continuously throughout the lifespan of a tooth, as new layers of dentin are deposited beneath the existing layers. Dentinogenesis is essential for tooth development and repair, as it provides strength and support to the tooth structure.
7.
Tissue fluid surrounding the cell membrane of the odontoblast in the dentinal tubules
Correct Answer
C. Dentinal fluid
Explanation
The correct answer is "Dentinal fluid" because it accurately describes the tissue fluid that surrounds the cell membrane of the odontoblast in the dentinal tubules. This fluid helps to nourish and hydrate the dentin, which is the hard tissue that makes up the majority of the tooth structure. Dentinal fluid also plays a role in the sensitivity of the tooth, as changes in fluid flow can cause pain or discomfort.
8.
Nutrition for dentin comes from....
Correct Answer
B. Through tissue fluid through tubules from pulp
Explanation
Dentin, which is the hard tissue that makes up the majority of a tooth, receives its nutrition from tissue fluid that flows through tiny channels called tubules. This fluid originates from the pulp, which is the innermost part of the tooth that contains blood vessels and nerves. The tissue fluid carries essential nutrients to nourish the dentin and maintain its health and integrity.
9.
Dentin types are determined by their ______________
Correct Answer
Location
Region
Relationship to DEJ
Relationship to dentinal tubules
Explanation
Dentin types are determined by their location, region, relationship to DEJ, and relationship to dentinal tubules. The different types of dentin can be classified based on where they are located within the tooth structure, such as coronal or radicular dentin. Region refers to the specific area within the tooth where the dentin is found, such as the pulp chamber or root canal. The relationship to DEJ (dentin-enamel junction) refers to the proximity of the dentin to the enamel layer. Lastly, the relationship to dentinal tubules refers to the presence and arrangement of the tiny tubular structures within the dentin.
10.
This type of dentin is around the outer pulpal wall & parallel to the DEJ
Correct Answer
Circumpulpal
Explanation
Circumpulpal dentin refers to the dentin that surrounds the pulp chamber and is parallel to the dentinoenamel junction (DEJ). It is located around the outer pulpal wall. This type of dentin provides support and protection to the pulp and is responsible for maintaining the structural integrity of the tooth.
11.
This type of dentin continues to form throughout the life of the tooth.
Correct Answer
Secondary
Explanation
Secondary dentin is a type of dentin that continues to form throughout the life of the tooth. It is formed as a response to various stimuli such as tooth decay, trauma, or aging. This type of dentin is produced by the odontoblasts, which are specialized cells located in the pulp of the tooth. Secondary dentin helps to protect the pulp by reducing the size of the pulp chamber as it forms. It is different from primary dentin, which forms during tooth development and stops forming once the tooth erupts into the mouth.
12.
This type of dentin is a type of tertiary dentin often found in chronic injury of caries.
Correct Answer
D. Sclerotic
Explanation
Sclerotic dentin is a type of tertiary dentin that is commonly found in cases of chronic injury caused by caries. Tertiary dentin is formed in response to external stimuli, such as dental caries, and is characterized by its irregular and disorganized structure. Sclerotic dentin, specifically, is formed when the dentinal tubules become occluded with mineral deposits, resulting in a hard and dense appearance. This type of dentin acts as a protective barrier against further damage and helps to maintain the structural integrity of the tooth.
13.
Attrition is the wearing away from tooth to tooth contact
Correct Answer
A. True
Explanation
Attrition refers to the gradual wearing away of tooth structure due to tooth-to-tooth contact, such as grinding or clenching. This can occur naturally over time or as a result of certain habits or conditions. Therefore, the statement "Attrition is the wearing away from tooth to tooth contact" is true as it accurately describes the process of attrition.
14.
Checkmark all of the functions of pulp
Correct Answer(s)
A. Sensory structure for pain
C. Nutrional supply for itself & dentin
D. Creates odontoblasts from fibroblasts
E. Immune response & inflammation by WBCs
Explanation
The correct answer includes the functions of pulp such as sensory structure for pain, nutritional supply for itself & dentin, creation of odontoblasts from fibroblasts, and immune response & inflammation by white blood cells. Pulp acts as a sensory structure for pain, allowing individuals to feel pain in their teeth. It also provides a nutritional supply for itself and dentin, ensuring the health and vitality of the tooth. Pulp is responsible for creating odontoblasts from fibroblasts, which are essential for dentin formation. Additionally, pulp plays a role in the immune response and inflammation by white blood cells, helping to fight off infections and promote healing.
15.
The _________ canal is an opening to the PDL and also known as a lateral canal.
Correct Answer(s)
Accessory
Explanation
The term "accessory" refers to something that is additional or supplementary. In this context, the "accessory canal" is an opening that connects to the periodontal ligament (PDL) and is also known as a lateral canal. This canal serves as an additional pathway for blood vessels and nerves to enter the tooth, providing support and nourishment to the surrounding tissues.
16.
Accessory canals form when HERS encounters a nerve
Correct Answer
B. False
Explanation
Accessory canals form when HERS encounters a blood vessel during root formation
17.
Checkmark all the features of pulp
Correct Answer(s)
B. Collagen fibers
C. Reticular fibers
D. Connective tissue
E. Mesenchymal stem cells
Explanation
The correct answer includes the features of collagen fibers, reticular fibers, connective tissue, and mesenchymal stem cells. Collagen fibers are the most abundant protein in the body and provide strength and support to tissues. Reticular fibers form a network that supports organs and tissues. Connective tissue connects and supports different structures in the body. Mesenchymal stem cells are multipotent cells that can differentiate into various cell types and play a crucial role in tissue repair and regeneration.
18.
Fibroblasts are the largest group of cells in pulp & Odontoblasts are the second largest.
Correct Answer
A. True
Explanation
The statement is true because fibroblasts are indeed the largest group of cells in pulp. Fibroblasts are responsible for producing the extracellular matrix in connective tissues, including the dental pulp. On the other hand, odontoblasts are the second largest group of cells in pulp. Odontoblasts are specialized cells that form dentin, which is the hard tissue that makes up the majority of the tooth structure.
19.
The ________ layer of pulp is next to dentin.
Correct Answer
Odondoblastic layer
Explanation
The odontoblastic layer is the layer of pulp that is adjacent to the dentin. The odontoblasts are specialized cells found in this layer that produce dentin, the hard tissue that forms the bulk of the tooth. These cells are responsible for the formation of dentin throughout the life of the tooth. Therefore, the odontoblastic layer is located directly next to the dentin.
20.
Calcified masses of dentin complete with tubules and processes
Correct Answer
Pulp stone
Pulp stones
Explanation
Pulp stones are calcified masses of dentin that are found within the pulp of a tooth. These stones are composed of dentin, which is the hard tissue that makes up the bulk of the tooth. Pulp stones can vary in size and shape and may contain tubules and processes, which are structures found within dentin. These stones can develop as a result of various factors, such as trauma, inflammation, or aging. Pulp stones are typically asymptomatic and are often discovered during routine dental examinations or radiographic imaging.
21.
Inflammation of the pulp caused by injury
Correct Answer
Pulpitis
Explanation
Pulpitis refers to the inflammation of the pulp, which is the innermost part of the tooth. It is commonly caused by injury or trauma to the tooth, such as a deep cavity, cracked tooth, or dental procedures. When the pulp becomes inflamed, it can cause severe pain, sensitivity, and swelling. If left untreated, pulpitis can progress to an infection or abscess. Therefore, prompt dental treatment is necessary to alleviate the inflammation and prevent further complications.
22.
The hardest calcified tissue in the body
Correct Answer
enamel
Explanation
Enamel is the hardest calcified tissue in the body. It is the outermost layer of the teeth and provides protection to the underlying dentin and pulp. Enamel is composed mainly of hydroxyapatite crystals, which make it extremely strong and resistant to wear and decay. Its hardness allows it to withstand the forces of biting and chewing. Enamel also has a smooth and shiny appearance, contributing to the aesthetic appeal of the teeth.
23.
Enamel cannot be removed
Correct Answer
B. False
Explanation
In a healthy state, enamel CAN be removed by a rotary cutting instrument or rough files
24.
Enamel can endure _________ lbs PSI
Correct Answer
B. 100,000
Explanation
Enamel, which is the hard outer layer of the teeth, is known for its durability. It can withstand a significant amount of pressure before any damage occurs. In this case, the correct answer is 100,000 lbs PSI, indicating that enamel can endure a high level of force, making it highly resistant to wear and tear.
25.
Dentin & pulp are more radio_______ than enamel on radiographs.
Correct Answer
radiolucent
darker
Explanation
Dentin and pulp are more radiolucent than enamel on radiographs, meaning that they appear darker on the X-ray image. This is because dentin and pulp have a lower density and absorb less radiation compared to enamel, which is denser and absorbs more radiation. As a result, dentin and pulp allow more X-rays to pass through, resulting in a darker appearance on the radiograph.
26.
Enamel is thinner in cervical areas & thicker at the masticatory surfaces.
Correct Answer
A. True
Explanation
Enamel is the outermost layer of the tooth and it varies in thickness depending on the location. The cervical areas, which are closer to the gum line, have thinner enamel compared to the masticatory surfaces, which are the areas where chewing occurs. This is because the cervical areas are more prone to erosion and wear, so they have a thinner layer of enamel for protection. On the other hand, the masticatory surfaces experience more force and pressure during chewing, so they have a thicker layer of enamel to withstand these forces. Therefore, the statement that enamel is thinner in cervical areas and thicker at the masticatory surfaces is true.
27.
The process of enamel matrix formation
Correct Answer
Amelogenesis
Explanation
Amelogenesis refers to the process of enamel matrix formation. It is the process by which the enamel, the hard outer layer of teeth, is formed. During amelogenesis, ameloblasts, specialized cells in the tooth germ, secrete organic matrix materials that eventually mineralize to form enamel. This process involves the deposition of hydroxyapatite crystals, which give enamel its strength and hardness. Amelogenesis is a complex and highly regulated process, involving various stages and molecular interactions, and it is essential for the development of healthy and functional teeth.
28.
The guiding factor or ____________ produces the enamel matrix during amelogenesis.
Correct Answer
A. Tomes Process
Explanation
The Tomes Process is responsible for producing the enamel matrix during amelogenesis. This process is found in the ameloblasts, which are specialized cells that form enamel. The Tomes Process is a structure within the ameloblasts that secretes and organizes the enamel matrix, which eventually mineralizes to form enamel. This process plays a crucial role in the development and formation of enamel, the outermost layer of the teeth.
29.
What embryonic layer is enamel derived from?
Correct Answer
C. Ectoderm
Explanation
Enamel, the hard outer layer of the teeth, is derived from the ectoderm. During tooth development, the ectoderm gives rise to the enamel organ, which eventually forms the enamel. The ectoderm is one of the three primary embryonic layers and is responsible for forming the outer covering of the body, including the skin, hair, nails, and enamel.
30.
Ameloblasts come from
Correct Answer
A. IEE
Explanation
Ameloblasts come from the Inner Enamel Epithelium (IEE). The IEE is a layer of cells located in the enamel organ of a developing tooth. These cells differentiate into ameloblasts, which are responsible for producing enamel, the hard outer covering of the tooth. The IEE is in close proximity to the dental papilla, which contains the cells that will differentiate into dentin-forming cells. Together, the ameloblasts and dentin-forming cells play a crucial role in the development and formation of a functional tooth.
31.
Enamel matrix initially is composed of protein, carbohydrates and a large amount of calcium hydroxiapatite crystals
Correct Answer
B. False
Explanation
Enamel matrix initially is composed of SMALL amounts of calcium hydroxiapatite crystals. Ameloblasts pump the crystals into enamel matrix.
32.
Amelogenins & enamelins are the 2 unique classes of proteins.
Correct Answer
A. True
Explanation
Amelogenins and enamelins are indeed the two unique classes of proteins found in enamel. These proteins play a crucial role in the formation and development of enamel, which is the outermost layer of the teeth. Amelogenins are primarily responsible for enamel matrix formation, while enamelins contribute to the enamel's structural integrity. The presence of these two protein classes distinguishes enamel from other types of tissues, making the statement "True."
33.
The Line of _________ transverse enamel rods.
Correct Answer
Retzius
Explanation
Another neonatal line!
34.
Imbrication lines associated with the Line of Retzius on nonmasticatory surfaces.
Correct Answer
Perikymata
Explanation
Perikymata refers to the fine, horizontal lines that are visible on the enamel surface of teeth. These lines are formed due to the incremental growth of enamel during tooth development. Imbrication lines, on the other hand, are associated with the Line of Retzius, which represents a band-like structure in the enamel. The Line of Retzius is formed by the periodic deposition of enamel during tooth development. Therefore, the presence of imbrication lines on nonmasticatory surfaces is not accurate, while perikymata is the correct term to describe the fine lines on the enamel surface.