CRDTS Periodontal Examination
Practice Exam 2026 | 100 Advanced
Questions & Answers with Detailed
Rationales | CRDTS Dental Licensing
Exam Prep & Study Guide
1. A patient presents with generalized bleeding on probing, 5–6 mm probing
depths, clinical attachment loss, and radiographic horizontal bone loss.
Which finding most strongly distinguishes periodontitis from gingivitis?
A. Gingival erythema
B. Bleeding on probing
C. Clinical attachment loss due to periodontal destruction
D. Gingival edema
Answer: Clinical attachment loss due to periodontal destruction
Rationale: Periodontitis is characterized by loss of periodontal attachment and
supporting bone. Gingivitis may produce bleeding, erythema, and edema but
does not cause destructive attachment loss.
, 2. During periodontal charting, a 6 mm probing depth is recorded on a tooth
with 3 mm of gingival recession. What is the approximate clinical
attachment level?
A. 3 mm
B. 6 mm
C. 9 mm
D. 12 mm
Answer: 9 mm
Rationale: When the gingival margin is apical to the CEJ, recession is added to
probing depth. CAL = probing depth + recession: 6 + 3 = 9 mm.
3. A patient has generalized periodontal pocketing but no radiographic
evidence of bone loss. Which condition should be considered first?
A. Stage IV periodontitis
B. Gingivitis with pseudopocketing
C. Necrotizing periodontitis
D. Aggressive periodontitis
Answer: Gingivitis with pseudopocketing
Rationale: Gingival enlargement can increase probing depths without
attachment loss or bone destruction. Radiographic and attachment findings help
distinguish a pseudopocket from a true periodontal pocket.
4. Which probing finding is most suggestive of a periodontal pocket rather
than a pseudopocket?
A. Increased probing depth with an intact CEJ relationship
B. Increased probing depth accompanied by clinical attachment loss
C. Bleeding without attachment loss
D. Enlarged interdental papillae
Answer: Increased probing depth accompanied by clinical attachment loss
,Rationale: A true periodontal pocket represents apical migration of the
junctional epithelium and loss of connective tissue attachment, whereas a
pseudopocket results primarily from gingival enlargement.
5. A molar demonstrates furcation involvement where the periodontal probe
enters the furcation but does not pass completely through. Which
classification is most appropriate?
A. Grade I
B. Grade II
C. Grade III
D. Grade IV
Answer: Grade II
Rationale: Grade II furcation involvement represents a horizontal defect with
partial penetration into the furcation. Grade III permits complete horizontal
passage through the furcation.
6. Which root morphology most significantly complicates periodontal
instrumentation in a multirooted tooth?
A. Short, widely separated roots
B. Fused roots with no concavities
C. Root concavities and closely positioned roots
D. Single conical root
Answer: Root concavities and closely positioned roots
Rationale: Root concavities, developmental grooves, and narrow interradicular
spaces make adaptation and calculus removal more difficult, particularly in
furcation areas.
7. A periodontal probe enters a furcation from the buccal aspect and can be
passed completely through to the lingual surface. What does this indicate?
A. Grade I furcation
B. Grade II furcation
, C. Grade III furcation
D. No furcation involvement
Answer: Grade III furcation
Rationale: Grade III furcation involvement is a through-and-through horizontal
defect, although the furcation may still be covered by soft tissue clinically.
8. A patient has generalized CAL of 4 mm, with localized areas of 6 mm and
radiographic bone loss extending into the middle third of the root. Which
clinical parameter is particularly important when determining periodontal
severity?
A. Tooth shade
B. Gingival pigmentation
C. Clinical attachment loss and radiographic bone loss
D. Occlusal anatomy alone
Answer: Clinical attachment loss and radiographic bone loss
Rationale: Periodontal severity is primarily evaluated using attachment loss,
radiographic bone loss, probing findings, tooth loss attributable to periodontitis,
and other complexity factors.
9. Which radiographic pattern is most characteristic of vertical periodontal
bone loss?
A. Bone loss parallel to the CEJ
B. Angular defect extending obliquely along the root surface
C. Uniform crestal height
D. Generalized widening of crowns
Answer: Angular defect extending obliquely along the root surface
Rationale: Vertical or angular bone defects occur when bone loss progresses at
an oblique angle relative to the tooth surface, producing an intrabony defect.
Practice Exam 2026 | 100 Advanced
Questions & Answers with Detailed
Rationales | CRDTS Dental Licensing
Exam Prep & Study Guide
1. A patient presents with generalized bleeding on probing, 5–6 mm probing
depths, clinical attachment loss, and radiographic horizontal bone loss.
Which finding most strongly distinguishes periodontitis from gingivitis?
A. Gingival erythema
B. Bleeding on probing
C. Clinical attachment loss due to periodontal destruction
D. Gingival edema
Answer: Clinical attachment loss due to periodontal destruction
Rationale: Periodontitis is characterized by loss of periodontal attachment and
supporting bone. Gingivitis may produce bleeding, erythema, and edema but
does not cause destructive attachment loss.
, 2. During periodontal charting, a 6 mm probing depth is recorded on a tooth
with 3 mm of gingival recession. What is the approximate clinical
attachment level?
A. 3 mm
B. 6 mm
C. 9 mm
D. 12 mm
Answer: 9 mm
Rationale: When the gingival margin is apical to the CEJ, recession is added to
probing depth. CAL = probing depth + recession: 6 + 3 = 9 mm.
3. A patient has generalized periodontal pocketing but no radiographic
evidence of bone loss. Which condition should be considered first?
A. Stage IV periodontitis
B. Gingivitis with pseudopocketing
C. Necrotizing periodontitis
D. Aggressive periodontitis
Answer: Gingivitis with pseudopocketing
Rationale: Gingival enlargement can increase probing depths without
attachment loss or bone destruction. Radiographic and attachment findings help
distinguish a pseudopocket from a true periodontal pocket.
4. Which probing finding is most suggestive of a periodontal pocket rather
than a pseudopocket?
A. Increased probing depth with an intact CEJ relationship
B. Increased probing depth accompanied by clinical attachment loss
C. Bleeding without attachment loss
D. Enlarged interdental papillae
Answer: Increased probing depth accompanied by clinical attachment loss
,Rationale: A true periodontal pocket represents apical migration of the
junctional epithelium and loss of connective tissue attachment, whereas a
pseudopocket results primarily from gingival enlargement.
5. A molar demonstrates furcation involvement where the periodontal probe
enters the furcation but does not pass completely through. Which
classification is most appropriate?
A. Grade I
B. Grade II
C. Grade III
D. Grade IV
Answer: Grade II
Rationale: Grade II furcation involvement represents a horizontal defect with
partial penetration into the furcation. Grade III permits complete horizontal
passage through the furcation.
6. Which root morphology most significantly complicates periodontal
instrumentation in a multirooted tooth?
A. Short, widely separated roots
B. Fused roots with no concavities
C. Root concavities and closely positioned roots
D. Single conical root
Answer: Root concavities and closely positioned roots
Rationale: Root concavities, developmental grooves, and narrow interradicular
spaces make adaptation and calculus removal more difficult, particularly in
furcation areas.
7. A periodontal probe enters a furcation from the buccal aspect and can be
passed completely through to the lingual surface. What does this indicate?
A. Grade I furcation
B. Grade II furcation
, C. Grade III furcation
D. No furcation involvement
Answer: Grade III furcation
Rationale: Grade III furcation involvement is a through-and-through horizontal
defect, although the furcation may still be covered by soft tissue clinically.
8. A patient has generalized CAL of 4 mm, with localized areas of 6 mm and
radiographic bone loss extending into the middle third of the root. Which
clinical parameter is particularly important when determining periodontal
severity?
A. Tooth shade
B. Gingival pigmentation
C. Clinical attachment loss and radiographic bone loss
D. Occlusal anatomy alone
Answer: Clinical attachment loss and radiographic bone loss
Rationale: Periodontal severity is primarily evaluated using attachment loss,
radiographic bone loss, probing findings, tooth loss attributable to periodontitis,
and other complexity factors.
9. Which radiographic pattern is most characteristic of vertical periodontal
bone loss?
A. Bone loss parallel to the CEJ
B. Angular defect extending obliquely along the root surface
C. Uniform crestal height
D. Generalized widening of crowns
Answer: Angular defect extending obliquely along the root surface
Rationale: Vertical or angular bone defects occur when bone loss progresses at
an oblique angle relative to the tooth surface, producing an intrabony defect.
