Dental MCQ
Will the tooth hold? · Periodontics · INBDE Patient Cases

Prognosis, Occlusion & Peri-Implant INBDE Patient Cases

By Dr. Isaac Sun, DDS

8 ADA INBDE-format patient cases on prognosis, occlusion & peri-implant. Each case is a shared patient box (chief complaint, history, medications, allergies, exam) followed by linked multiple-choice questions with full distractor explanations. Practice the way the real exam is structured.

8 patient cases40 linked questionsADA INBDE formatFull distractor explanations

Eight ADA INBDE-format patient cases on the periodontal decision, framed by the Structural Decision Framework: a hopeless molar with a Class III furcation and severe mobility that should be extracted, a reduced but stable periodontium worth maintaining in a low-risk adherent patient, primary occlusal trauma from a high crown on an intact periodontium, secondary occlusal trauma in a bruxer with reduced support, perio-restorative sequencing where periodontal health must precede definitive crowns, peri-implant mucositis versus peri-implantitis with a history of periodontitis as a risk factor, a diabetic smoker whose risk factors worsen prognosis, and an SDF synthesis running Structure, Force, Time, and Stability on one tooth. Topics include periodontal prognosis, the maintain-versus-extract decision, occlusal trauma, perio-systemic and perio-restorative interfaces, and peri-implant disease.

Case Coverage Map
What each case is testing
A tooth that cannot be saved:
Hopeless prognosis (Structure: minimal attachment, Class III furcation, mobility), extraction, threat to neighbors, and the prosthodontic handoff for replacement.
Reduced bone, but stable and worth keeping:
Good prognosis on a reduced periodontium, the Time and Stability lenses, and continued supportive periodontal therapy in a low-risk patient.
A high crown loosening an otherwise healthy tooth:
Primary occlusal trauma, the widened PDL and mobility, occlusal adjustment, and that occlusal trauma does not initiate periodontitis.
A bruxer with reduced support:
Secondary occlusal trauma (Force lens), the guard/splint plus inflammation control, and why inflammation control is essential.
Crowns wanted, but the gums aren't ready:
Perio-restorative sequencing, establishing periodontal health first, respecting the supracrestal attachment, and the Time-lens risk of restoring on active disease.
Inflammation around an implant:
Peri-implant mucositis (reversible) versus peri-implantitis (bone loss), periodontitis history as a risk factor, and why peri-implantitis is harder to treat.
Risk factors that tilt the decision:
Diabetes and smoking worsening prognosis (Stability lens), risk-factor control, and stabilize-then-reassess for questionable teeth.
Running all four lenses on one tooth:
An SDF synthesis: Structure (reduced but usable, Class II furcation), Force (bruxism), Time (controlled), and Stability (the integrated maintain-and-regenerate plan).
Patient case: A tooth that cannot be saved
0 of 5 answered, 0 correct
Patient
Male, 63 years old
Chief Complaint
A very loose back tooth that is hard to clean and sore.
Background and/or Patient History
  • Molar with severe attachment loss, Class III (through-and-through) furcation, and Class 3 mobility
  • Minimal remaining bone support
  • Adjacent teeth are restorable
Allergies
NKDA
Medications
  • None
Current Findings
  • Severe bone loss, through-and-through furcation, depressible mobility
  • Tooth not maintainable
  1. Question 1
    Moderate
    Through the Structure lens, this tooth's reserve is:
  2. Question 2
    Moderate
    This prognosis is best described as:
  3. Question 3
    Moderate
    The appropriate decision for this tooth is:
  4. Question 4
    Moderate
    A reason not to retain this hopeless tooth is that it may:
  5. Question 5
    Easy
    Replacing the extracted tooth with an implant or bridge is:

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Patient case: Reduced bone, but stable and worth keeping
0 of 5 answered, 0 correct
Patient
Female, 58 years old
Chief Complaint
Treated periodontitis; wondering if her teeth can be kept long-term.
Background and/or Patient History
  • Previously treated periodontitis with reduced but stable attachment
  • No bleeding on probing; excellent adherence to maintenance and home care
  • Non-smoker, no diabetes
Allergies
NKDA
Medications
  • None
Current Findings
  • Reduced but stable periodontium; no active disease
  • Low-risk, adherent patient
  1. Question 1
    Moderate
    A reduced but stable periodontium in this adherent, low-risk patient is:
  2. Question 2
    Moderate
    Through the Time lens, this patient is:
  3. Question 3
    Moderate
    Through the Stability lens, what most supports keeping these teeth?
  4. Question 4
    Moderate
    Her ongoing care should be:
  5. Question 5
    Moderate
    This case shows that prognosis depends on:

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Patient case: A high crown loosening an otherwise healthy tooth
0 of 5 answered, 0 correct
Patient
Male, 45 years old
Chief Complaint
A tooth feels loose and sore to bite since a new crown was placed.
Background and/or Patient History
  • New crown left in hyperocclusion (a high contact)
  • The tooth has an otherwise normal, intact periodontium
  • Increased mobility and discomfort on biting
Allergies
NKDA
Medications
  • None
Current Findings
  • Increased mobility and fremitus; widened PDL space on radiograph
  • Healthy periodontium apart from the trauma
  1. Question 1
    Moderate
    Excessive force on this otherwise normal, intact periodontium is:
  2. Question 2
    Moderate
    The widened PDL space and increased mobility here reflect:
  3. Question 3
    Moderate
    The most direct management is to:
  4. Question 4
    Moderate
    Because the periodontium is otherwise healthy, the prognosis after correcting the occlusion is:
  5. Question 5
    Moderate
    This case shows that occlusal trauma by itself:

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Patient case: A bruxer with reduced support
0 of 5 answered, 0 correct
Patient
Female, 56 years old
Chief Complaint
Loose teeth that are getting worse; grinds at night.
Background and/or Patient History
  • Treated periodontitis with reduced bone support
  • Heavy nocturnal bruxism; increasing mobility of several teeth
  • Inflammation currently controlled
Allergies
NKDA
Medications
  • None
Current Findings
  • Normal-to-heavy occlusal forces on a periodontium reduced by prior disease
  • Increasing mobility and fremitus; parafunction
  1. Question 1
    Moderate
    Occlusal force on this periodontium already reduced by disease is:
  2. Question 2
    Moderate
    Through the Force lens, the bruxism matters because it:
  3. Question 3
    Moderate
    Appropriate management includes:
  4. Question 4
    Hard
    Why is controlling inflammation essential even though the problem is occlusal?
  5. Question 5
    Moderate
    Through the Stability lens, long-term success here depends on:

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Patient case: Crowns wanted, but the gums aren't ready
0 of 5 answered, 0 correct
Patient
Male, 52 years old
Chief Complaint
Wants new crowns on several teeth.
Background and/or Patient History
  • Active generalized periodontitis with bleeding and deep pockets
  • Requests definitive crowns now
  • Some proposed margins would be subgingival
Allergies
NKDA
Medications
  • None
Current Findings
  • Active periodontal disease; unstable gingival margins
  • Restorative plan pending
  1. Question 1
    Moderate
    Before placing definitive crowns, the clinician should:
  2. Question 2
    Moderate
    Restoring on an inflamed, unstable periodontium tends to cause:
  3. Question 3
    Moderate
    If proposed margins would encroach on the supracrestal attachment, the clinician should:
  4. Question 4
    Easy
    This sequencing reflects the principle that:
  5. Question 5
    Moderate
    Through the Time lens, restoring now (with active disease) would:

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Patient case: Inflammation around an implant
0 of 5 answered, 0 correct
Patient
Female, 60 years old
Chief Complaint
Bleeding and redness around an implant placed a few years ago.
Background and/or Patient History
  • History of treated periodontitis; now has an implant
  • Bleeding on probing around the implant; plaque present
  • Question of whether bone has been lost
Allergies
NKDA
Medications
  • None
Current Findings
  • Peri-implant soft-tissue inflammation with bleeding; assessing for bone loss
  • History of periodontitis and current plaque accumulation
  1. Question 1
    Moderate
    Peri-implant inflammation with bleeding but no bone loss is:
  2. Question 2
    Moderate
    If progressive bone loss is also present, the diagnosis becomes:
  3. Question 3
    Moderate
    This patient's history of periodontitis is relevant because it:
  4. Question 4
    Moderate
    Management of peri-implant mucositis centers on:
  5. Question 5
    Hard
    Compared with periodontitis around a tooth, established peri-implantitis is generally:

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Patient case: Risk factors that tilt the decision
0 of 5 answered, 0 correct
Patient
Male, 55 years old
Chief Complaint
Moderate-to-severe periodontitis; deciding which teeth to keep.
Background and/or Patient History
  • Poorly controlled type 2 diabetes (high HbA1c) and a heavy smoker
  • Several teeth with questionable prognosis
  • Inconsistent maintenance attendance
Allergies
NKDA
Medications
  • Metformin
Current Findings
  • Multiple questionable-prognosis teeth in a high-risk host
  • Major modifiable risk factors present
  1. Question 1
    Moderate
    How do poorly controlled diabetes and heavy smoking affect the prognosis of the questionable teeth?
  2. Question 2
    Moderate
    Through the Stability lens, these risk factors mean:
  3. Question 3
    Moderate
    A key part of improving the prognosis is to:
  4. Question 4
    Moderate
    For teeth of questionable prognosis in this high-risk patient, a reasonable approach is to:
  5. Question 5
    Easy
    The role of risk factors in the decision illustrates that prognosis is:

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Patient case: Running all four lenses on one tooth
0 of 5 answered, 0 correct
Patient
Female, 59 years old
Chief Complaint
Deciding whether to keep a periodontally involved molar.
Background and/or Patient History
  • Molar with moderate bone loss and a Class II furcation, but a usable amount of attachment remains
  • Mild bruxism; inflammation currently controlled; adherent to maintenance
  • Non-smoker; well-controlled health
Allergies
NKDA
Medications
  • None
Current Findings
  • Reduced but workable attachment with a Class II furcation; controlled inflammation
  • Low systemic risk and good adherence
  1. Question 1
    Moderate
    Through the Structure lens, this tooth is:
  2. Question 2
    Moderate
    Through the Force lens, the mild bruxism calls for:
  3. Question 3
    Moderate
    Through the Time lens, this tooth is currently:
  4. Question 4
    Hard
    Through the Stability lens, the overall plan that gives this tooth a good long-term outlook is:
  5. Question 5
    Moderate
    This synthesis case shows that the SDF lenses together:

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Keep studying
Prognosis, Occlusion & Peri-Implant core recall

Refresh the anatomy facts these cases depend on: nerve numbers, foramina, functions, and lesion findings.

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