CDCA/ADEX Practice Exam | 100 Questions
CDCA / ADEX DENTAL LICENSING EXAM QUESTIONS
AND CORRECT DETAILED ANSWERS WITH RATIONALES
LATEST 2026-2027 (VERIFIED ANSWERS) ALREADY
GRADED A+
100 Practice Questions with Rationales
Instructions: Select the single BEST answer for each question. Correct answers are indicated in bold.
1. A 45-year-old patient presents with white, non-scrapable lesions on the lateral border of the tongue.
The patient is HIV-positive. Which of the following is the MOST likely diagnosis?
A. Candidiasis
B. Hairy leukoplakia
C. Lichen planus
D. Leukoplakia
Rationale: Hairy leukoplakia is caused by Epstein-Barr virus (EBV) and is strongly associated with HIV
infection. It appears as white, corrugated (hairy), non-scrapable lesions on the lateral border of the tongue.
Candidiasis is scrapable. Lichen planus has a bilateral, lacy (Wickham's striae) pattern. Simple leukoplakia is
a diagnosis of exclusion not specifically tied to EBV.
2. Which of the following local anesthetics has the LONGEST duration of action?
A. Lidocaine
B. Mepivacaine
C. Prilocaine
D. Bupivacaine
Rationale: Bupivacaine (Marcaine) has the longest duration of action among the listed agents, lasting up to
8–12 hours with a vasoconstrictor. It is an amide anesthetic used when prolonged anesthesia is needed.
Lidocaine and mepivacaine have intermediate durations, while prilocaine also has an intermediate duration
and is noted for causing methemoglobinemia in high doses.
3. A patient presents with a periapical abscess on tooth #9. The tooth is non-vital. Which of the
following is the MOST appropriate initial treatment?
A. Extraction of the tooth
B. Incision and drainage only
C. Root canal therapy and possible incision and drainage
D. Antibiotic therapy alone
Rationale: The gold standard for treating a periapical abscess on a non-vital tooth is to address the source of
infection through root canal therapy (RCT), which removes the infected pulpal tissue. If fluctuance is present,
incision and drainage (I&D) is performed adjunctively. Antibiotics alone do not address the source. Extraction
is an option but is a more destructive approach when the tooth can be saved.
4. Which of the following radiographic findings is MOST consistent with a periapical cemento-osseous
dysplasia (PCOD) in its mature stage?
A. Radiolucent lesion at the apex
B. Mixed radiolucent/radiopaque lesion with a radiolucent rim
Page 1 of 26
, CDCA/ADEX Practice Exam | 100 Questions
C. Completely radiopaque lesion with a radiolucent rim
D. Diffuse radiopacity without defined borders
Rationale: Periapical cemento-osseous dysplasia (PCOD) goes through three stages: early (radiolucent),
intermediate (mixed), and mature (radiopaque with a radiolucent rim/halo). In the mature stage, the lesion
becomes densely calcified but retains a thin radiolucent rim from the fibrous capsule surrounding it. The teeth
are vital, distinguishing this from periapical pathology of pulpal origin.
5. Overhanging margins on Class II amalgam restorations MOST commonly lead to which of the
following?
A. Secondary caries only
B. Localized bone loss and periodontal disease
C. Pulpal necrosis
D. Tooth sensitivity
Rationale: Overhanging amalgam margins act as plaque-retentive areas that are difficult to clean. This leads
to accumulation of subgingival plaque and calculus, resulting in localized periodontal disease with
inflammation, attachment loss, and alveolar bone loss. While secondary caries can also occur, the MOST
clinically significant consequence is periodontal breakdown at the site.
6. The primary infection with herpes simplex virus type 1 (HSV-1) in children typically presents as which
of the following?
A. Herpes labialis (cold sores)
B. Primary herpetic gingivostomatitis
C. Herpes zoster
D. Herpangina
Rationale: Primary HSV-1 infection in children most commonly manifests as acute herpetic gingivostomatitis,
characterized by fever, malaise, regional lymphadenopathy, and multiple painful vesicles and ulcers on the
gingiva and oral mucosa. Herpes labialis (cold sores) represents recurrent HSV-1 infection. Herpes zoster is
caused by varicella-zoster virus. Herpangina is caused by coxsackievirus.
7. Which of the following instruments is BEST used for scaling and root planing in deep, narrow
periodontal pockets?
A. Universal curette
B. Gracey curette
C. Sickle scaler
D. Hoe scaler
Rationale: Gracey curettes are area-specific instruments designed for scaling and root planing in specific
areas of the mouth. Their offset blade angle (70°) allows only one cutting edge to be adapted to the root
surface, making them ideal for deep, narrow pockets and furcations. Universal curettes can be used
throughout the mouth but are less precise in deep, narrow pockets. Sickle scalers are for supragingival
deposits only.
8. Which of the following is the MOST appropriate treatment for a Class III furcation involvement in a
mandibular molar?
A. Scaling and root planing only
B. Furcationplasty
C. Guided tissue regeneration
Page 2 of 26
, CDCA/ADEX Practice Exam | 100 Questions
D. Extraction or root amputation/hemisection
Rationale: Class III furcation involvement means the probe passes completely through the furcation from one
side to the other (through-and-through). The prognosis of such teeth is generally poor, and the most
appropriate treatments are either extraction or hemisection/root amputation if the anatomy is favorable.
Scaling and root planing is insufficient. GTR has limited success in Class III furcations.
9. A patient takes warfarin (Coumadin). Before performing a surgical procedure, the dentist should
consult the patient's physician and review which laboratory value?
A. Partial thromboplastin time (PTT)
B. Platelet count
C. International Normalized Ratio (INR)
D. Bleeding time
Rationale: Warfarin is a vitamin K antagonist that affects the extrinsic and common coagulation pathways.
The INR (International Normalized Ratio) is the standardized measure of prothrombin time and is used to
monitor warfarin therapy. A therapeutic INR is 2.0–3.0 for most indications. PTT monitors heparin therapy.
Platelet count monitors platelet disorders. Bleeding time is used to assess primary hemostasis/platelet
function.
10. Which of the following describes the correct sequence for placing a rubber dam clamp?
A. Clamp, dam, then frame
B. Frame, dam, then clamp
C. Dam, frame, then clamp
D. Any sequence is acceptable
Rationale: The recommended sequence for rubber dam placement is: (1) place the clamp on the anchor
tooth first (with floss tied to it for retrieval), (2) then stretch the dam over the clamp bow and wings, (3) then
place the frame to hold the dam taut. Placing the clamp first ensures it is correctly seated and reduces the risk
of the dam being displaced before it is secured.
11. Which cell type is PRIMARILY responsible for bone resorption during periodontal disease?
A. Osteoblasts
B. Osteocytes
C. Osteoclasts
D. Fibroblasts
Rationale: Osteoclasts are multinucleated giant cells derived from monocyte/macrophage precursors that are
responsible for bone resorption. During periodontal disease, inflammatory mediators (IL-1, TNF-α, PGE2,
RANKL) stimulate osteoclast differentiation and activity, leading to alveolar bone loss. Osteoblasts form bone.
Osteocytes maintain bone matrix. Fibroblasts produce collagen and maintain connective tissue.
12. A patient presents with smooth surface caries on the proximal surfaces of posterior teeth. Which of
the following restorative materials is MOST appropriate for a Class II restoration that requires both
strength and esthetics?
A. Glass ionomer cement
B. Composite resin
C. Amalgam
D. Zinc phosphate cement
Page 3 of 26
CDCA / ADEX DENTAL LICENSING EXAM QUESTIONS
AND CORRECT DETAILED ANSWERS WITH RATIONALES
LATEST 2026-2027 (VERIFIED ANSWERS) ALREADY
GRADED A+
100 Practice Questions with Rationales
Instructions: Select the single BEST answer for each question. Correct answers are indicated in bold.
1. A 45-year-old patient presents with white, non-scrapable lesions on the lateral border of the tongue.
The patient is HIV-positive. Which of the following is the MOST likely diagnosis?
A. Candidiasis
B. Hairy leukoplakia
C. Lichen planus
D. Leukoplakia
Rationale: Hairy leukoplakia is caused by Epstein-Barr virus (EBV) and is strongly associated with HIV
infection. It appears as white, corrugated (hairy), non-scrapable lesions on the lateral border of the tongue.
Candidiasis is scrapable. Lichen planus has a bilateral, lacy (Wickham's striae) pattern. Simple leukoplakia is
a diagnosis of exclusion not specifically tied to EBV.
2. Which of the following local anesthetics has the LONGEST duration of action?
A. Lidocaine
B. Mepivacaine
C. Prilocaine
D. Bupivacaine
Rationale: Bupivacaine (Marcaine) has the longest duration of action among the listed agents, lasting up to
8–12 hours with a vasoconstrictor. It is an amide anesthetic used when prolonged anesthesia is needed.
Lidocaine and mepivacaine have intermediate durations, while prilocaine also has an intermediate duration
and is noted for causing methemoglobinemia in high doses.
3. A patient presents with a periapical abscess on tooth #9. The tooth is non-vital. Which of the
following is the MOST appropriate initial treatment?
A. Extraction of the tooth
B. Incision and drainage only
C. Root canal therapy and possible incision and drainage
D. Antibiotic therapy alone
Rationale: The gold standard for treating a periapical abscess on a non-vital tooth is to address the source of
infection through root canal therapy (RCT), which removes the infected pulpal tissue. If fluctuance is present,
incision and drainage (I&D) is performed adjunctively. Antibiotics alone do not address the source. Extraction
is an option but is a more destructive approach when the tooth can be saved.
4. Which of the following radiographic findings is MOST consistent with a periapical cemento-osseous
dysplasia (PCOD) in its mature stage?
A. Radiolucent lesion at the apex
B. Mixed radiolucent/radiopaque lesion with a radiolucent rim
Page 1 of 26
, CDCA/ADEX Practice Exam | 100 Questions
C. Completely radiopaque lesion with a radiolucent rim
D. Diffuse radiopacity without defined borders
Rationale: Periapical cemento-osseous dysplasia (PCOD) goes through three stages: early (radiolucent),
intermediate (mixed), and mature (radiopaque with a radiolucent rim/halo). In the mature stage, the lesion
becomes densely calcified but retains a thin radiolucent rim from the fibrous capsule surrounding it. The teeth
are vital, distinguishing this from periapical pathology of pulpal origin.
5. Overhanging margins on Class II amalgam restorations MOST commonly lead to which of the
following?
A. Secondary caries only
B. Localized bone loss and periodontal disease
C. Pulpal necrosis
D. Tooth sensitivity
Rationale: Overhanging amalgam margins act as plaque-retentive areas that are difficult to clean. This leads
to accumulation of subgingival plaque and calculus, resulting in localized periodontal disease with
inflammation, attachment loss, and alveolar bone loss. While secondary caries can also occur, the MOST
clinically significant consequence is periodontal breakdown at the site.
6. The primary infection with herpes simplex virus type 1 (HSV-1) in children typically presents as which
of the following?
A. Herpes labialis (cold sores)
B. Primary herpetic gingivostomatitis
C. Herpes zoster
D. Herpangina
Rationale: Primary HSV-1 infection in children most commonly manifests as acute herpetic gingivostomatitis,
characterized by fever, malaise, regional lymphadenopathy, and multiple painful vesicles and ulcers on the
gingiva and oral mucosa. Herpes labialis (cold sores) represents recurrent HSV-1 infection. Herpes zoster is
caused by varicella-zoster virus. Herpangina is caused by coxsackievirus.
7. Which of the following instruments is BEST used for scaling and root planing in deep, narrow
periodontal pockets?
A. Universal curette
B. Gracey curette
C. Sickle scaler
D. Hoe scaler
Rationale: Gracey curettes are area-specific instruments designed for scaling and root planing in specific
areas of the mouth. Their offset blade angle (70°) allows only one cutting edge to be adapted to the root
surface, making them ideal for deep, narrow pockets and furcations. Universal curettes can be used
throughout the mouth but are less precise in deep, narrow pockets. Sickle scalers are for supragingival
deposits only.
8. Which of the following is the MOST appropriate treatment for a Class III furcation involvement in a
mandibular molar?
A. Scaling and root planing only
B. Furcationplasty
C. Guided tissue regeneration
Page 2 of 26
, CDCA/ADEX Practice Exam | 100 Questions
D. Extraction or root amputation/hemisection
Rationale: Class III furcation involvement means the probe passes completely through the furcation from one
side to the other (through-and-through). The prognosis of such teeth is generally poor, and the most
appropriate treatments are either extraction or hemisection/root amputation if the anatomy is favorable.
Scaling and root planing is insufficient. GTR has limited success in Class III furcations.
9. A patient takes warfarin (Coumadin). Before performing a surgical procedure, the dentist should
consult the patient's physician and review which laboratory value?
A. Partial thromboplastin time (PTT)
B. Platelet count
C. International Normalized Ratio (INR)
D. Bleeding time
Rationale: Warfarin is a vitamin K antagonist that affects the extrinsic and common coagulation pathways.
The INR (International Normalized Ratio) is the standardized measure of prothrombin time and is used to
monitor warfarin therapy. A therapeutic INR is 2.0–3.0 for most indications. PTT monitors heparin therapy.
Platelet count monitors platelet disorders. Bleeding time is used to assess primary hemostasis/platelet
function.
10. Which of the following describes the correct sequence for placing a rubber dam clamp?
A. Clamp, dam, then frame
B. Frame, dam, then clamp
C. Dam, frame, then clamp
D. Any sequence is acceptable
Rationale: The recommended sequence for rubber dam placement is: (1) place the clamp on the anchor
tooth first (with floss tied to it for retrieval), (2) then stretch the dam over the clamp bow and wings, (3) then
place the frame to hold the dam taut. Placing the clamp first ensures it is correctly seated and reduces the risk
of the dam being displaced before it is secured.
11. Which cell type is PRIMARILY responsible for bone resorption during periodontal disease?
A. Osteoblasts
B. Osteocytes
C. Osteoclasts
D. Fibroblasts
Rationale: Osteoclasts are multinucleated giant cells derived from monocyte/macrophage precursors that are
responsible for bone resorption. During periodontal disease, inflammatory mediators (IL-1, TNF-α, PGE2,
RANKL) stimulate osteoclast differentiation and activity, leading to alveolar bone loss. Osteoblasts form bone.
Osteocytes maintain bone matrix. Fibroblasts produce collagen and maintain connective tissue.
12. A patient presents with smooth surface caries on the proximal surfaces of posterior teeth. Which of
the following restorative materials is MOST appropriate for a Class II restoration that requires both
strength and esthetics?
A. Glass ionomer cement
B. Composite resin
C. Amalgam
D. Zinc phosphate cement
Page 3 of 26
