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Implants: INBDE study notes and practice questions

Implant questions cover whether a patient is a candidate, how bone and soft tissue are managed, how the prosthesis is designed, and how to recognize and treat peri-implant disease.

181 practice questions · 10 patient cases

Practice Implants

Where it fits in the official INBDE blueprint

Oral Health Management (implant procedures). Nearest foundation knowledge area: FK 3. See the content outline for the official weights. This mapping is approximate: real items combine a clinical area with a foundation area.

What this area tests

High-yield checklist

Common traps

These notes are original study aids, not official exam content. Confirm clinical details against current guidelines.

Sample questions

1. When placing a screw-retained implant crown, how much minimum occlusal space is needed from the implant platform to the opposing dentition?

  1. 5 mm
  2. 8 mm
  3. 7 mm
  4. 9 mm
Show answer and explanation

Correct answer: A. 5 mm

✓ A) 5 mm is the minimum.
For a screw-retained implant crown, a minimum of 5 mm of vertical restorative space is required from the implant platform to the opposing occlusal surface. This accommodates the implant component (abutment) and the crown material. For cement-retained crowns, ~5 mm is also standard, though some clinicians cite 8 mm for ideal prosthetic space for both types combined with biologic considerations.

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2. A 45-year-old male is interested in implant placement. Each of the following is a cytokine that aids in the stability and success of an implant EXCEPT one. Which is the EXCEPTION?

  1. Interleukin-1
  2. Bone morphogenetic protein-4
  3. Tumor necrosis factor-alpha
  4. Transforming growth factor-beta-1
Show answer and explanation

Correct answer: A. Interleukin-1

TGF-β1 and BMP-4 promote bone formation and healing around implants. TNF-alpha, while pro-inflammatory, plays a complex role but when chronically elevated is detrimental. IL-1 is strongly pro-inflammatory and when elevated chronically leads to bone resorption and implant failure — it is the cytokine that does NOT aid implant stability.
  • A. CORRECT. Interleukin-1 (IL-1) is a pro-inflammatory cytokine. Chronically elevated IL-1 stimulates osteoclasts and promotes bone resorption, which is detrimental to implant osseointegration and stability.
  • B. INCORRECT. BMP-4 (Bone Morphogenetic Protein-4) is osteoinductive — it directly stimulates osteoblast differentiation and bone formation, strongly AIDING implant stability.
  • C. INCORRECT. TNF-alpha has complex roles but can promote early healing; it is also pro-inflammatory and when chronically elevated can harm implants. IL-1 is the better 'exception' answer.
  • D. INCORRECT. TGF-β1 (Transforming Growth Factor beta-1) promotes extracellular matrix production, cell proliferation, and bone healing — it AIDS implant stability.

Note: ⚠️ FLAG: The source lists IL-1 as the exception. IL-1 and TNF-α are both pro-inflammatory. IL-1 is the better answer here as it is most consistently associated with peri-implant bone loss when overexpressed.

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3. Primary stability of a temporary anchorage device (TAD) most relies on:

  1. Length of the TAD
  2. Diameter of the TAD
  3. Cortical bone thickness
  4. Keratinization of the tissue
Show answer and explanation

Correct answer: C. Cortical bone thickness

Cortical bone thickness is the most critical factor for primary (initial) stability of TADs. Thin cortical bone (e.g., posterior maxilla) significantly increases immediate failure risk when the TAD is loaded. Secondary stability via osseointegration is not desired for TADs as they are temporary.

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4. Typical MINIMUM number of implants for a full-arch maxillary implant-supported overdenture?

  1. 6
  2. 2
  3. 4
  4. 8
Show answer and explanation

Correct answer: C. 4

Minimum 4 implants for full-arch maxillary overdenture (All-on-4 concept). Some protocols use 6 for added stability. Mandible can be rehabilitated with 2 implants (Hader bar or locator attachments). Maxilla requires more due to lower bone density.

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5. What is the recommended minimum distance between two adjacent dental implants?

  1. 1.5 mm
  2. 3 mm
  3. 2 mm
  4. 4 mm
Show answer and explanation

Correct answer: B. 3 mm

The recommended minimum distance between two adjacent dental implants is 3 mm (center-to-center distance of the implant platforms minus the implant diameters). This spacing is necessary to preserve the interimplant bone (crestal bone between implants), allow for proper osseointegration, maintain adequate blood supply to the interimplant bone, and accommodate papilla formation for esthetics. Inadequate spacing leads to crestal bone loss between implants, which can compromise long-term implant survival and esthetics.

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6. If the distance from the alveolar bone to the inferior alveolar nerve (IAN) is 10 mm, what is the maximum implant length that can be used?

  1. 7 mm
  2. 10 mm
  3. 8 mm
  4. 9 mm
Show answer and explanation

Correct answer: C. 8 mm

A 2 mm safety margin must be maintained between the apex of the implant and the superior border of the inferior alveolar nerve canal. With 10 mm of available bone from the alveolar crest to the IAN, subtracting the 2 mm safety margin leaves 8 mm for the implant. Maximum implant length = Available bone height − 2 mm safety margin = 10 − 2 = 8 mm.
  • A. INCORRECT. 7 mm would leave 3 mm from the IAN — while safe, it is not the MAXIMUM length available.
  • B. INCORRECT. 10 mm would place the implant apex directly at the IAN — this would cause nerve damage.
  • C. CORRECT. Maximum implant length = 10 mm (bone height) − 2 mm (safety margin from IAN) = 8 mm. This is the longest implant that can be placed while maintaining adequate safety from the nerve.
  • D. INCORRECT. 9 mm would leave only 1 mm from the IAN — insufficient safety margin, risking nerve injury.

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7. Why is zirconia resistant to CORROSION compared to titanium?

  1. Zirconia forms a corrosion-resistant oxide layer like titanium
  2. Zirconia is a ceramic (metal oxide) — no metal ions to release or corrode; intrinsically corrosion-free
  3. Zirconia has a surface coating that prevents corrosion
  4. Zirconia corrodes the same as titanium
  5. Zirconia corrodes in acid environments
Show answer and explanation

Correct answer: B. Zirconia is a ceramic (metal oxide) — no metal ions to release or corrode; intrinsically corrosion-free

✓ B) Zirconia is a ceramic (ZrO₂ — zirconium oxide) — no metallic ions to corrode.
Zirconia (Y-TZP): is ZIRCONIUM DIOXIDE — a metal oxide CERAMIC. Unlike metallic titanium which can (rarely) release metal ions (causing local tissue reactions, especially in metal-sensitive patients), zirconia is chemically inert. No galvanic corrosion, no metal ion release, no discoloration of peri-implant tissues (titanium oxide can cause grey tissue tinting). This makes zirconia particularly advantageous in: thin gingival biotypes (no dark show-through), patients with metal sensitivity, patients who want all-white/metal-free restorations.

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8. Each of the following molecules plays a significant role in OSTEOINDUCTION EXCEPT one. Which is the EXCEPTION?

  1. Transforming growth factor-beta (TGF-β)
  2. Bone morphogenetic protein (BMP)
  3. Interleukin-8 (IL-8)
  4. Fibroblast growth factor (FGF)
Show answer and explanation

Correct answer: C. Interleukin-8 (IL-8)

Osteoinduction involves molecules that stimulate undifferentiated cells to become bone-forming cells. BMP is THE classic osteoinductive molecule — it directly stimulates mesenchymal cells to differentiate into osteoblasts. TGF-β promotes bone matrix formation. FGF stimulates osteoblast proliferation. IL-8 is a pro-inflammatory CHEMOKINE that recruits neutrophils and macrophages to sites of infection/injury — it is NOT osteoinductive. It is involved in inflammation, not bone formation.
  • A. INCORRECT — TGF-β promotes osteoblast proliferation and matrix production, and is a significant mediator of osteoinduction and bone repair.
  • B. INCORRECT — BMPs (bone morphogenetic proteins) are the MOST potent known osteoinductive factors, capable of inducing bone formation de novo. BMP-2 and BMP-7 are FDA-approved for clinical use.
  • C. CORRECT (EXCEPTION) — Interleukin-8 (IL-8) is primarily a pro-inflammatory chemokine that attracts neutrophils; it plays a role in inflammation but is NOT a primary mediator of osteoinduction.
  • D. INCORRECT — FGF promotes osteoblast proliferation and angiogenesis, playing a role in bone formation and osteoinduction.

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Patient cases

All Implants questions (181)