COA COA Orthodontic Materials & Equipment 1 — Questions and Answers
Question 1: What type of material is most commonly used to bond orthodontic brackets to teeth?
- Zinc phosphate cement
- Composite resin (Correct answer)
- Glass ionomer cement
- Zinc oxide eugenol
Correct answer: Composite resin
Composite resin is the most widely used bonding material for orthodontic brackets due to its strong adhesion and good aesthetics.
Question 2: Which instrument is used to remove excess bonding material from around newly placed brackets?
- Scaler (Correct answer)
- Explorer
- Hemostat
- Band pusher
Correct answer: Scaler
A scaler is used to scrape away excess composite resin from around the bracket base before curing.
Question 3: What is the primary purpose of orthodontic separators (spacers)?
- To hold archwires in place
- To create space between teeth before band placement (Correct answer)
- To protect brackets from damage
- To align teeth rapidly
Correct answer: To create space between teeth before band placement
Orthodontic separators are placed between contact points to create space for fitting orthodontic bands around molar teeth.
Question 4: Which archwire material has the highest elastic memory and is most commonly used during initial alignment?
- Stainless steel
- Cobalt-chromium
- Nickel-titanium (NiTi) (Correct answer)
- Beta-titanium
Correct answer: Nickel-titanium (NiTi)
Nickel-titanium wire has superior elastic memory and delivers light, continuous forces ideal for the initial alignment phase of treatment.
Question 5: What gauge ligature wire is most commonly used in orthodontics to tie archwires to brackets?
- 0.009 inch (Correct answer)
- 0.010 inch
- 0.012 inch
- 0.014 inch
Correct answer: 0.009 inch
0.009-inch stainless steel ligature wire is the standard gauge used to cinch archwires into bracket slots.
Question 6: What is the function of an open coil spring placed on an archwire?
- To retain tooth position after treatment
- To open (create) space between teeth (Correct answer)
- To close spaces between teeth
- To expand the palate
Correct answer: To open (create) space between teeth
An open coil spring pushes adjacent teeth apart, creating space for tooth movement or implant placement.
COA COA Orthodontic Materials & Equipment 1
What type of material is most commonly used to bond orthodontic brackets to teeth?