CIT Equipment Operation & Maintenance 3 — Questions and Answers
Question 1: What is the critical bone temperature threshold above which thermal necrosis and implant failure risk significantly increase?
- 37°C
- 42°C
- 47°C (Correct answer)
- 56°C
Correct answer: 47°C
Research by Eriksson and Albrektsson established 47°C as the critical threshold; sustained heat above this level for more than one minute causes irreversible bone cell death.
Question 2: A piezoelectric surgical unit's tip shows visible chip fractures. The correct action is to:
- Continue use at lower power settings
- Replace the tip immediately before next use (Correct answer)
- Autoclave the tip and inspect again
- Apply composite resin to fill the fracture
Correct answer: Replace the tip immediately before next use
A fractured piezo tip must be replaced immediately because the fragment can become a foreign body in the surgical site and tip efficiency is severely compromised.
Question 3: Which connection type between implant motor and handpiece uses a bayonet-style twist-lock mechanism?
- ISO E-type connection (Correct answer)
- ISO B-type connection
- Luer-lock connection
- KaVo Multiflex coupling
Correct answer: ISO E-type connection
The ISO E-type (electric) coupling uses a bayonet-style twist-lock mechanism that allows handpiece attachment and detachment with a quarter-turn rotation.
Question 4: During sequential drilling protocol, the technician notices the third drill is not advancing smoothly and requires excessive force. The best response is to:
- Increase motor RPM to push through dense bone
- Remove the drill, irrigate, and inspect for wear before continuing (Correct answer)
- Switch to a larger diameter drill to create more space
- Apply downward pressure with both hands to advance the drill
Correct answer: Remove the drill, irrigate, and inspect for wear before continuing
Excessive resistance often indicates a worn or clogged drill; removing, irrigating, and inspecting prevents thermal damage and drill breakage inside the osteotomy.
Question 5: What is the function of the anti-retraction valve in an implant motor irrigation system?
- It regulates saline pressure to prevent bone fracture
- It prevents oral fluids from being aspirated back into the tubing (Correct answer)
- It controls the direction of water flow to the bur tip
- It filters particulates from the saline before delivery
Correct answer: It prevents oral fluids from being aspirated back into the tubing
The anti-retraction valve prevents negative pressure from pulling potentially contaminated oral fluids back into the handpiece tubing, reducing cross-contamination risk.
Question 6: How should an implant technician verify that a surgical handpiece is functioning at its calibrated speed before a procedure?
- Run the handpiece in open air and listen for the correct pitch
- Use a tachometer or optical RPM sensor to measure actual output speed (Correct answer)
- Compare the motor display reading with the manufacturer's chart
- Test drill penetration depth in a wax block
Correct answer: Use a tachometer or optical RPM sensor to measure actual output speed
A calibrated tachometer or optical RPM sensor provides an objective, measurable confirmation that the handpiece delivers the speed indicated by the motor's control unit.
Question 7: Which component of an implant surgical unit is most susceptible to damage from high-level disinfectant chemical immersion?
- Stainless steel drill shanks
- Titanium implant drivers
- Handpiece cord/cable assembly (Correct answer)
- Sterile saline reservoir bag
Correct answer: Handpiece cord/cable assembly
Handpiece cord assemblies contain electrical wiring and polymeric insulators that degrade when immersed in harsh chemical disinfectants, which are contraindicated for these components.
CIT Equipment Operation & Maintenance 3
What is the critical bone temperature threshold above which thermal necrosis and implant failure risk significantly increase?