Free INBDE Practice Questions: 10 Case-Based Questions With Answers (2026)
Here are 10 free, original INBDE practice questions with full answers: 6 patient-box cases and 4 single-concept questions, written in the real exam’s one-best-answer format. Each explanation teaches the concept first, applies it to the case, then shows why every wrong option is wrong, with the current guideline cited underneath.
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Try the 10 questions below, then see the full INBDE course blueprint.
What the real INBDE looks like
From the JCNDE’s INBDE 2026 Candidate Guide (updated 4 August 2026). Knowing the format tells you how to practise.
| Day | Sections | Time you get per question |
|---|---|---|
| Day 1 | 3 sections of 100 standalone questions, then 1 section of 60 case questions | About 63 seconds (standalone); 1 min 45 s (cases) |
| Day 2 | 2 sections of 70 case questions | About 1 min 30 s |
One best answerEvery question is multiple choice with 3 to 5 options and one correct or best answer. Negative words such as EXCEPT, LEAST and NOT are capitalised.
The patient boxCases give you a patient box. If an area is empty, treat that information as unknown. No allergies listed means no known allergies.
Where the marks areOral Health Management 42%, Diagnosis and Treatment Planning 36%, Practice and Profession 22%.
For eligibility, fees and booking, read our complete INBDE exam guide. The official INBDE practice questions on the JCNDE website are good for learning the screen and item format, but the JCNDE itself warns they may be outdated.
10 INBDE practice questions with answers
Original questions written by The Study Boards faculty. They are not real or recalled exam items. Give yourself 13 minutes for all 10, close to real exam pace. Commit to an answer, then open the explanation, and tick the box if you got it right.
Patient: 7-year-old girl. Height 122 cm. Weight 26 kg.
Chief complaint: “My tooth hurts when I eat sweets.”
Medical history: Healthy. Medications: None. Allergies: None known.
Vitals: BP 100/62 mmHg, pulse 92/min, respiration 20/min.
Findings: Deep caries on primary teeth K and L. Both need a pulpotomy and a stainless steel crown today. You plan an inferior alveolar nerve block and a buccal infiltration with articaine 4% with epinephrine 1:100,000. Each cartridge holds 1.7 mL.
What is the maximum dose of articaine you can give her at this visit?
Show answer and explanation
Answer: B Topic: pharmacology, local anesthesia
The idea: maximum dose = mg per kg x body weight in kg. To turn that into cartridges, work out the mg in one cartridge: a 4% solution has 40 mg per mL, so a 1.7 mL cartridge holds 68 mg. The manufacturer’s maximum for articaine is 7 mg/kg, and it is not recommended under 4 years of age.
Apply it: 7 mg x 26 kg = 182 mg. 182 / 68 = 2.7 cartridges. So she can have no more than 2 full cartridges and part of a third, and you should always use the lowest dose that gives effective anesthesia.
Why the others are wrong: A uses 4.4 mg/kg, the AAPD figure for lidocaine and mepivacaine, not articaine. C divides by 34 mg, the content of a 2% lidocaine cartridge; articaine 4% has twice as much drug per cartridge. D multiplies 7 mg by her weight in pounds (57 lb) instead of kilograms, which would more than double the safe dose.
Source: AAPD, Best Practices: Use of Local Anesthesia for Pediatric Dental Patients (Reference Manual, table of injectable local anesthetics); FDA label for Septocaine (articaine HCl with epinephrine), DailyMed, section 2.2.
Patient: 67-year-old man. Height 178 cm. Weight 84 kg.
Chief complaint: “My gums bleed when I brush.”
Medical history: Severe aortic stenosis, treated with a transcatheter aortic valve replacement (TAVR) 2 years ago. High blood pressure.
Medications: Aspirin 81 mg daily, lisinopril 20 mg daily, atorvastatin 40 mg daily.
Allergies: Amoxicillin. He developed hives over his whole body in 2019.
Vitals: BP 128/78 mmHg, pulse 72/min, respiration 16/min.
Findings: Generalized 5 to 6 mm pockets with bleeding on probing. Scaling and root planing of the upper right and lower right quadrants is planned for today.
Which premedication is most appropriate before today’s appointment?
Show answer and explanation
Answer: D Topic: pharmacology, infective endocarditis prophylaxis
The idea: the 2021 AHA statement keeps prophylaxis for the highest-risk heart patients: prosthetic valves (including transcatheter valves) or valve-repair material, previous infective endocarditis, certain congenital heart disease, and heart transplants with valve disease. It covers procedures that manipulate the gingiva or periapical region, or perforate the mucosa. Adults take one oral dose 30 to 60 minutes before: amoxicillin 2 g, or, with a penicillin allergy, cephalexin 2 g, azithromycin or clarithromycin 500 mg, or doxycycline 100 mg. No cephalosporin after anaphylaxis, angioedema or hives with penicillin. Clindamycin is no longer recommended.
Apply it: a TAVR is a prosthetic valve, and scaling and root planing manipulates the gingiva, so he needs prophylaxis. He had hives with amoxicillin, which rules out amoxicillin and cephalexin. Azithromycin 500 mg fits.
Why the others are wrong: A is the drug he is allergic to. B is a cephalosporin, which the guideline excludes after hives with penicillin. C was dropped in 2021 because it causes more frequent and more severe reactions, including C. difficile infection. E is wrong because a transcatheter valve counts as a prosthetic valve. If a dose is missed, it can still be given up to 2 hours after the procedure.
Source: Wilson WR et al. Prevention of Viridans Group Streptococcal Infective Endocarditis: A Scientific Statement From the AHA. Circulation 2021, Table 5; ADA Oral Health Topics, Antibiotic Prophylaxis Prior to Dental Procedures.
Patient: 34-year-old man.
Chief complaint: “My gums bleed, and a lower back tooth feels loose.”
Medical history: No diabetes; HbA1c 5.3% last month. Smokes 6 cigarettes a day. Medications: None.
Vitals: BP 118/76 mmHg, pulse 76/min, respiration 14/min.
Findings: Bleeding on probing at most sites. Probing depths of 5 to 6 mm on 14 of his 28 teeth. Worst interdental clinical attachment loss is 6 mm, on #19 and #30. #19 has mobility of degree 1 and a Class I furcation. Radiographs show horizontal bone loss; the worst site, on #19, has lost 40% of the root length. No teeth have been lost to periodontitis. There are no earlier radiographs or charts.
Using the 2017 classification, what is his diagnosis?
Show answer and explanation
Answer: C Topic: periodontics, 2017 classification
The idea: the stage measures severity and complexity, starting from the worst interdental attachment loss. The grade measures how fast the disease is moving. Start every patient at Grade B, then look for evidence to move to A or C. With no old records, use the bone loss at the worst site divided by the patient’s age:
| Grade | % bone loss / age | Smoking | Diabetes |
|---|---|---|---|
| A (slow) | under 0.25 | Non-smoker | No diabetes |
| B (moderate) | 0.25 to 1.0 | Under 10 a day | HbA1c under 7.0% |
| C (rapid) | over 1.0 | 10 or more a day | HbA1c 7.0% or more |
Apply it: attachment loss of 6 mm, bone loss into the middle third of the root (40%) and 6 mm pockets make this Stage III. The grade ratio is 40 / 34 = 1.18, which is over 1.0, so Grade C. Pockets on 14 of 28 teeth (50%) make it generalized.
Why the others are wrong: A needs 3 to 4 mm of attachment loss and bone loss in the coronal third. B stops at the smoking history. Six cigarettes a day only supports Grade B, but risk factors such as smoking can push a grade up; they do not pull down a grade the bone-loss ratio has already set. D needs 5 or more teeth lost to periodontitis or a need for complex rehabilitation, such as bite collapse. E is wrong twice: localized means under 30% of teeth, and Grade A needs a ratio under 0.25.
Source: Tonetti MS, Greenwell H, Kornman KS. Staging and grading of periodontitis. J Periodontol 2018;89(Suppl 1):S159-S172, as summarised in the AAP chart Staging and Grading Periodontitis.
Patient: 29-year-old woman.
Chief complaint: “My lower left back tooth has been throbbing since last night. Cold water makes it much worse, and it hurts to chew.”
Medical history: Healthy. Medications: None.
Vitals: BP 116/74 mmHg, pulse 84/min, respiration 16/min.
Findings: #19 has a large MO composite with recurrent caries at the mesial margin. Cold test on #19: sharp, intense pain that lasts about 60 seconds after the ice is removed. Cold on #18 and #20: a brief response that stops when the ice is removed. Percussion on #19: painful. Palpation: normal. Probing depths 3 mm or less. Periapical radiograph: the restoration is close to the mesial pulp horn; the PDL space and lamina dura at the apex look normal.
What is the pulpal and apical diagnosis for #19?
Show answer and explanation
Answer: C Topic: endodontics, AAE diagnostic terms
The idea: an endodontic diagnosis has a pulp half and an apical half. Symptomatic irreversible pulpitis means a living pulp that is inflamed and cannot heal; its signs are lingering thermal pain, spontaneous pain and referred pain. Symptomatic apical periodontitis means pain on biting, percussion or palpation, and the AAE states it may or may not show a radiolucency.
Apply it: throbbing since last night is spontaneous pain, and cold pain that lingers for a minute shows the pulp cannot recover. The tooth hurts to chew and to tap, so the apical half is symptomatic apical periodontitis, even though the radiograph is normal.
Why the others are wrong: A fits pain that stops as soon as the cold is removed, with no spontaneous pain. B is the trap: it reads the radiograph and ignores the painful percussion. D is for a tooth with no symptoms; this patient woke up in pain. E needs a pulp that does not respond to testing, plus swelling or pus; this pulp responds strongly.
Source: American Association of Endodontists, AAE Consensus Conference Recommended Diagnostic Terminology.
Patient: 44-year-old Black woman, new patient.
Chief complaint: “Nothing hurts. I’m here for a check-up.”
Medical history: Hypothyroidism. Medications: Levothyroxine 75 mcg daily.
Vitals: BP 114/72 mmHg, pulse 70/min, respiration 14/min.
Findings: #23 to #26 have no caries, no restorations and no history of trauma. Normal colour, no mobility, probing depths 3 mm or less, no swelling or bone expansion. Cold test: all four teeth give a normal, brief response. Percussion and palpation: normal. Periapical radiograph: well-defined radiolucent areas at the apices of #24 and #25, each with small radiopaque spots in the centre, and a similar fully radiolucent area at the apex of #23.
What is the most appropriate management?
Show answer and explanation
Answer: D Topic: oral pathology, periapical cemento-osseous dysplasia
The idea: periapical cemento-osseous dysplasia is a benign, non-neoplastic bone lesion at the apices of the mandibular anterior teeth. It is most common in middle-aged women of African and East Asian descent. The teeth test vital. On radiographs it starts radiolucent, becomes mixed, and can end up fully radiopaque. An asymptomatic lesion needs no treatment, only periodic review. The lesional bone has a poor blood supply, so surgery can lead to infection.
Apply it: she fits the typical patient, the teeth are vital, and nothing could have infected the pulps (no caries, restorations or trauma). Lesions at different stages, radiolucent at #23 and mixed at #24 and #25, are typical.
Why the others are wrong: A treats healthy, vital pulps; mistaking these lesions for apical periodontitis is the classic error. B is not needed for a typical, symptom-free picture, and surgery on this poorly vascular bone invites infection. C treats an infection that is not there. E removes healthy teeth.
Source: PathologyOutlines.com, Cemento-osseous dysplasia (citing Head Neck Pathol 2020;14:70 and J Korean Assoc Oral Maxillofac Surg 2022;48:79).
Patient: 8-year-old boy. Weight 27 kg.
Chief complaint: His mother says: “He fell at football practice and his front tooth came out.”
Medical history: Healthy. Vaccinations, including tetanus, are up to date. Medications: None.
Vitals: BP 102/64 mmHg, pulse 104/min (upset), respiration 22/min.
Findings: #8 was knocked out 40 minutes ago. His coach put it straight into a cup of cold milk, and it arrives in the milk. The root is intact and clean, and the apex is wide open. The socket is intact. Radiographs show no fracture of the alveolar bone. #9 is normal.
You replant #8. What is the most appropriate plan after replantation?
Show answer and explanation
Answer: B Topic: pediatric dentistry, dental trauma
The idea: under the 2020 IADT guidelines, milk and Hanks’ Balanced Salt Solution are physiologic storage media. A replanted tooth gets a passive, flexible splint for 2 weeks, systemic antibiotics and a tetanus check. A more rigid splint for about 4 weeks is only for an alveolar or jaw fracture. With an open apex the pulp can revascularize, so root canal treatment waits for definite signs of necrosis and infection. With a closed apex, root canal treatment starts within 2 weeks.
Apply it: milk storage, an open apex and no bone fracture: flexible splint for 2 weeks, antibiotics, and close follow-up for signs of necrosis.
Why the others are wrong: A is the plan for a closed apex. C and D use a rigid, long splint that is only for bone fractures. E throws away the best option; replanting keeps future treatment choices open even if the tooth later fails.
Source: Fouad AF et al. IADT guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2020;36:331-342.
A composite resin restoration is placed in each of these preparations. Which preparation has the highest configuration factor (C-factor)?
Show answer and explanation
Answer: A Topic: restorative dentistry, dental materials
The idea: composite shrinks as it sets. The C-factor is the ratio of bonded surfaces to unbonded (free) surfaces. Free surfaces let the setting composite flow and relieve stress. The more walls the composite is bonded to, the more shrinkage stress builds up at the bond, which can open gaps at the margins.
Apply it: a Class I box is bonded to the pulpal floor and four walls, with only the occlusal surface free: a C-factor of about 5, the highest of these options.
Why the others are wrong: Class II and Class III preparations have more free surfaces, with C-factors of about 1 to 2. A Class IV restoration has several free surfaces and a C-factor of 1 or less. A direct veneer is bonded on one side and free on the other, a C-factor of about 1. (A box-shaped Class V preparation is also around 5, which is why it is left out here.)
Source: Feilzer AJ, De Gee AJ, Davidson CL. Setting stress in composite resin in relation to configuration of the restoration. J Dent Res 1987;66:1636-1639.
A periapical radiograph shows an unerupted maxillary canine crown overlapping the root of the lateral incisor. A second image is taken with the tube head shifted mesially. On it, the canine crown appears to move mesially relative to the lateral incisor root. Where is the canine?
Show answer and explanation
Answer: B Topic: oral radiology, buccal object rule
The idea: the buccal object rule (Clark’s rule, 1909) compares two images taken with the tube shifted between them. An object on the lingual or palatal side moves in the same direction as the tube. An object on the buccal side moves in the opposite direction. The short form is SLOB: Same Lingual, Opposite Buccal.
Apply it: the tube moved mesially and the canine moved mesially too, the same direction, so the canine is palatal.
Why the others are wrong: a buccal canine (A) would move distally, against the tube. Two objects in the same plane (C) would not move relative to each other. D is wrong because the two shifted images are exactly what the rule needs; cone-beam CT adds 3D detail when the full picture is needed, but it is not required to answer this.
Source: Dinu S et al. Radiographic methods for locating impacted maxillary canines. Rom J Morphol Embryol 2022.
A new caries-detection device is tested on 200 molars, with histology as the gold standard. The results are below. What is the specificity of the device?
| Caries present (80) | Caries absent (120) | |
|---|---|---|
| Device positive | 72 | 24 |
| Device negative | 8 | 96 |
Show answer and explanation
Answer: B Topic: biostatistics, diagnostic tests
The idea: name the four cells first: true positives (72), false positives (24), false negatives (8), true negatives (96). Then:
| Measure | Formula | Question it answers |
|---|---|---|
| Sensitivity | TP / (TP + FN) | Of the teeth with caries, how many did the device catch? |
| Specificity | TN / (TN + FP) | Of the sound teeth, how many did it correctly clear? |
| Positive predictive value | TP / (TP + FP) | If the device says caries, how often is it right? |
| Negative predictive value | TN / (TN + FN) | If the device says sound, how often is it right? |
Apply it: specificity = 96 / (96 + 24) = 96 / 120 = 80%.
Why the others are wrong: each is another measure from the same table. A is the positive predictive value (72 / 96). C is the sensitivity (72 / 80). D is the negative predictive value (96 / 104). Remember that predictive values change with how common the disease is in the group tested.
Source: Trevethan R. Sensitivity, Specificity, and Predictive Values: Foundations, Pliabilities, and Pitfalls in Research and Practice. Front Public Health 2017;5:307.
A patient left your practice owing $640. Her new dentist asks you for copies of her radiographs and treatment records. What should you do?
Show answer and explanation
Answer: B Topic: ethics, ADA Code
The idea: Section 1.B of the ADA Code (under the principle of patient autonomy) requires dentists to provide, on request of the patient or another dentist and in line with applicable law, any information that will help the patient’s future treatment. Advisory Opinion 1.B.1 adds that records or copies, including radiographs, are furnished free or for a nominal cost, and that this duty exists whether or not the account is paid in full.
Apply it: the new dentist needs her records to treat her. Send them. Collect the unpaid bill separately, the way you would any other debt.
Why the others are wrong: A and C hold her care hostage to the debt, which the Code rules out; a copying fee must be nominal. D misses the point: whoever keeps the original record, the dentist still owes the patient the information. E withholds treatment notes the new dentist needs; Section 1.B covers any information that will help her future treatment, not radiographs alone.
Source: ADA Principles of Ethics and Code of Professional Conduct, Section 1.B and Advisory Opinion 1.B.1.
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References
- JCNDE. INBDE 2026 Candidate Guide (updated 08/04/2026): item formats, patient box, test specifications, administration schedule, confidentiality. jcnde.ada.org
- ADA Department of Testing Services. Recent and Forthcoming Updates to Examinations (updated 09/23/2026). jcnde.ada.org
- AAPD. Best Practices: Use of Local Anesthesia for Pediatric Dental Patients. aapd.org; Septocaine prescribing information, DailyMed
- Wilson WR et al. Prevention of Viridans Group Streptococcal Infective Endocarditis. Circulation 2021. ahajournals.org; ADA, Antibiotic Prophylaxis Prior to Dental Procedures. ada.org
- Tonetti MS, Greenwell H, Kornman KS. J Periodontol 2018;89(Suppl 1):S159-S172; AAP Staging and Grading chart. perio.org
- AAE Consensus Conference Recommended Diagnostic Terminology. aae.org
- PathologyOutlines.com. Cemento-osseous dysplasia. pathologyoutlines.com
- Fouad AF et al. IADT guidelines: 2. Avulsion of permanent teeth. Dent Traumatol 2020;36:331-342. doi.org/10.1111/edt.12573
- Feilzer AJ, De Gee AJ, Davidson CL. J Dent Res 1987;66(11):1636-1639. doi.org/10.1177/00220345870660110601
- Dinu S et al. Radiographic methods for locating impacted maxillary canines. Rom J Morphol Embryol 2022. ncbi.nlm.nih.gov
- Trevethan R. Sensitivity, Specificity, and Predictive Values. Front Public Health 2017;5:307. doi.org/10.3389/fpubh.2017.00307
- ADA Principles of Ethics and Code of Professional Conduct, Section 1.B. ada.org
- The Study Boards: INBDE course blueprint and question bank pages. parmjitllc.com
Current as of October 2026. The 10 practice questions and explanations are original content written by The Study Boards faculty, not exam items. Exam format comes from the JCNDE INBDE 2026 Candidate Guide; confirm current rules with the JCNDE before you apply. Educational content, not clinical advice.