CDT COMPREHENSIVE EXAM AND
PRACTICE EXAM LATEST UPDATE 2025
ACTUAL EXAM COMPLETE QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS AND RATIONALE) |ALREADY
GRADED A+
Question: What is the primary purpose of a dental impression?
Answer: The primary purpose of a dental impression is to create an accurate
negative mold of the oral cavity, which is used to produce models for various
dental prosthetics, such as crowns, bridges, dentures, and orthodontic appliances.
Rationale: Dental impressions are critical in providing a replica of the teeth and
oral structures, enabling the technician to fabricate precise dental restorations or
appliances. This allows for proper fit and function when the restoration is placed in
the patient's mouth.
Question: Which of the following materials is most commonly used for the
fabrication of crowns?
Answer: Porcelain is commonly used for the fabrication of crowns.
Rationale: Porcelain is a popular choice for crowns due to its aesthetic qualities,
as it closely mimics the natural appearance of teeth. It is durable and can be color-
matched to the patient’s natural tooth shade, making it ideal for visible areas in the
mouth.
Question: What does the term "occlusion" refer to in dental terminology?
,Answer: Occlusion refers to the way the upper and lower teeth come together
when the mouth is closed.
Rationale: Proper occlusion is essential for overall dental health. It affects biting,
chewing, and the wear patterns of teeth. Malocclusion can lead to various
problems, including TMJ disorders, tooth wear, and discomfort.
Question: How is the success of a dental implant typically determined?
Answer: The success of a dental implant is typically determined by factors such as
the stability of the implant in the bone, the absence of infection, and the successful
integration of the implant with the surrounding bone (osseointegration).
Rationale: Implant success relies on its ability to integrate with the bone structure
to provide stable support for a crown or prosthetic. Lack of osseointegration or
infection can lead to implant failure.
Question: What is the function of a dental bridge?
Answer: A dental bridge is used to replace one or more missing teeth by
connecting an artificial tooth (or teeth) to adjacent natural teeth or dental implants.
Rationale: A bridge serves to restore function and aesthetics by filling the gap
created by missing teeth. It helps in maintaining the alignment of remaining teeth
and provides a more comfortable chewing experience for the patient.
Question: What is the most common cause of tooth decay?
Answer: The most common cause of tooth decay is the buildup of plaque on the
teeth, which harbors bacteria that produce acids that dissolve tooth enamel.
Rationale: Tooth decay occurs when acids from bacteria in plaque erode the
enamel, leading to cavities. Good oral hygiene practices, such as brushing and
flossing, are essential in preventing plaque buildup.
,Question: What is the role of fluoride in oral health?
Answer: Fluoride helps to remineralize tooth enamel and makes it more resistant
to acid attacks from bacteria in plaque.
Rationale: Fluoride is a key element in preventing tooth decay by strengthening
enamel and preventing the breakdown of minerals in the tooth structure. It can be
found in toothpaste and professional treatments, as well as in drinking water in
many regions.
Question: What is the difference between a partial denture and a full denture?
Answer: A partial denture is used when some natural teeth remain, while a full
denture is used when all teeth are missing.
Rationale: Partial dentures are designed to fit around the remaining teeth, whereas
full dentures replace all teeth in either the upper or lower arch. Both types aim to
restore function and appearance.
Question: What is the function of a dental retainer?
Answer: A dental retainer is used to maintain the position of teeth after
orthodontic treatment.
Rationale: Retainers help prevent teeth from shifting back to their original
positions after the removal of braces. They ensure that the results from orthodontic
treatment are stable and long-lasting.
Question: How do you identify the right size for an orthodontic bracket?
Answer: The right size for an orthodontic bracket is determined by the width of
the patient's tooth and the specific requirements of the treatment plan.
Rationale: Properly sized brackets ensure that the forces applied during
orthodontic treatment are evenly distributed. This helps in achieving the desired
alignment while minimizing discomfort or injury to the tooth structure.
, Question: What is the purpose of using a biting block in prosthodontics?
Answer: A biting block is used to help record the vertical dimension of occlusion
and to ensure proper alignment and occlusion in dentures or other prosthetic
devices.
Rationale: The vertical dimension of occlusion is crucial for proper function,
speech, and aesthetics. Biting blocks are designed to allow for the precise
determination of this dimension.
Question: What is the primary purpose of a dental crown?
Answer: The primary purpose of a dental crown is to restore a damaged or
decayed tooth to its original shape, size, and function while providing protection
from further damage.
Rationale: Crowns are often used when a tooth is severely decayed, cracked, or
weakened. By covering the tooth, the crown strengthens it and restores its function
for chewing and biting. Crowns also improve aesthetics in visible areas.
Question: What is the role of a dental alloy in the construction of dental
prosthetics?
Answer: Dental alloys are used to create durable, biocompatible prosthetics such
as crowns, bridges, and dentures.
Rationale: Dental alloys are composed of metals like gold, silver, or palladium
and are designed to be strong, long-lasting, and resistant to corrosion. Their use in
prosthetics ensures that restorations perform well in the harsh environment of the
mouth.
PRACTICE EXAM LATEST UPDATE 2025
ACTUAL EXAM COMPLETE QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS AND RATIONALE) |ALREADY
GRADED A+
Question: What is the primary purpose of a dental impression?
Answer: The primary purpose of a dental impression is to create an accurate
negative mold of the oral cavity, which is used to produce models for various
dental prosthetics, such as crowns, bridges, dentures, and orthodontic appliances.
Rationale: Dental impressions are critical in providing a replica of the teeth and
oral structures, enabling the technician to fabricate precise dental restorations or
appliances. This allows for proper fit and function when the restoration is placed in
the patient's mouth.
Question: Which of the following materials is most commonly used for the
fabrication of crowns?
Answer: Porcelain is commonly used for the fabrication of crowns.
Rationale: Porcelain is a popular choice for crowns due to its aesthetic qualities,
as it closely mimics the natural appearance of teeth. It is durable and can be color-
matched to the patient’s natural tooth shade, making it ideal for visible areas in the
mouth.
Question: What does the term "occlusion" refer to in dental terminology?
,Answer: Occlusion refers to the way the upper and lower teeth come together
when the mouth is closed.
Rationale: Proper occlusion is essential for overall dental health. It affects biting,
chewing, and the wear patterns of teeth. Malocclusion can lead to various
problems, including TMJ disorders, tooth wear, and discomfort.
Question: How is the success of a dental implant typically determined?
Answer: The success of a dental implant is typically determined by factors such as
the stability of the implant in the bone, the absence of infection, and the successful
integration of the implant with the surrounding bone (osseointegration).
Rationale: Implant success relies on its ability to integrate with the bone structure
to provide stable support for a crown or prosthetic. Lack of osseointegration or
infection can lead to implant failure.
Question: What is the function of a dental bridge?
Answer: A dental bridge is used to replace one or more missing teeth by
connecting an artificial tooth (or teeth) to adjacent natural teeth or dental implants.
Rationale: A bridge serves to restore function and aesthetics by filling the gap
created by missing teeth. It helps in maintaining the alignment of remaining teeth
and provides a more comfortable chewing experience for the patient.
Question: What is the most common cause of tooth decay?
Answer: The most common cause of tooth decay is the buildup of plaque on the
teeth, which harbors bacteria that produce acids that dissolve tooth enamel.
Rationale: Tooth decay occurs when acids from bacteria in plaque erode the
enamel, leading to cavities. Good oral hygiene practices, such as brushing and
flossing, are essential in preventing plaque buildup.
,Question: What is the role of fluoride in oral health?
Answer: Fluoride helps to remineralize tooth enamel and makes it more resistant
to acid attacks from bacteria in plaque.
Rationale: Fluoride is a key element in preventing tooth decay by strengthening
enamel and preventing the breakdown of minerals in the tooth structure. It can be
found in toothpaste and professional treatments, as well as in drinking water in
many regions.
Question: What is the difference between a partial denture and a full denture?
Answer: A partial denture is used when some natural teeth remain, while a full
denture is used when all teeth are missing.
Rationale: Partial dentures are designed to fit around the remaining teeth, whereas
full dentures replace all teeth in either the upper or lower arch. Both types aim to
restore function and appearance.
Question: What is the function of a dental retainer?
Answer: A dental retainer is used to maintain the position of teeth after
orthodontic treatment.
Rationale: Retainers help prevent teeth from shifting back to their original
positions after the removal of braces. They ensure that the results from orthodontic
treatment are stable and long-lasting.
Question: How do you identify the right size for an orthodontic bracket?
Answer: The right size for an orthodontic bracket is determined by the width of
the patient's tooth and the specific requirements of the treatment plan.
Rationale: Properly sized brackets ensure that the forces applied during
orthodontic treatment are evenly distributed. This helps in achieving the desired
alignment while minimizing discomfort or injury to the tooth structure.
, Question: What is the purpose of using a biting block in prosthodontics?
Answer: A biting block is used to help record the vertical dimension of occlusion
and to ensure proper alignment and occlusion in dentures or other prosthetic
devices.
Rationale: The vertical dimension of occlusion is crucial for proper function,
speech, and aesthetics. Biting blocks are designed to allow for the precise
determination of this dimension.
Question: What is the primary purpose of a dental crown?
Answer: The primary purpose of a dental crown is to restore a damaged or
decayed tooth to its original shape, size, and function while providing protection
from further damage.
Rationale: Crowns are often used when a tooth is severely decayed, cracked, or
weakened. By covering the tooth, the crown strengthens it and restores its function
for chewing and biting. Crowns also improve aesthetics in visible areas.
Question: What is the role of a dental alloy in the construction of dental
prosthetics?
Answer: Dental alloys are used to create durable, biocompatible prosthetics such
as crowns, bridges, and dentures.
Rationale: Dental alloys are composed of metals like gold, silver, or palladium
and are designed to be strong, long-lasting, and resistant to corrosion. Their use in
prosthetics ensures that restorations perform well in the harsh environment of the
mouth.
