Orthodontic and Periodontal Materials Practice Questions
20 free Orthodontic and Periodontal Materials practice questions for the CDA. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Which material is most commonly used for fixed orthodontic brackets?
- A Zinc phosphate
- B Stainless steel
- C Polyether
- D Glass ionomer
Correct answer: Stainless steel
Stainless steel provides strength, durability, and corrosion resistance. It is the most widely used material for orthodontic brackets.
What is the primary purpose of orthodontic archwires?
- A To bond brackets to the enamel
- B To maintain space after extraction
- C To apply continuous force to move teeth
- D To reinforce periodontal ligament fibers
Correct answer: To apply continuous force to move teeth
Archwires deliver the mechanical forces needed to move teeth into desired positions. They work in conjunction with brackets for effective tooth movement.
Which archwire material exhibits shape memory and superelasticity?
- A Stainless steel
- B Nickel-titanium (NiTi)
- C Cobalt-chromium
- D Titanium-molybdenum alloy
Correct answer: Nickel-titanium (NiTi)
NiTi wires are known for shape memory and flexibility, providing light, continuous force. They are widely used during initial alignment.
Elastomeric ligatures are used in orthodontics primarily to:
- A Bond brackets
- B Secure archwires into bracket slots
- C Measure periodontal pocket depth
- D Retain removable appliances
Correct answer: Secure archwires into bracket slots
Elastomeric ligatures hold archwires in place within brackets. They are available in various colors and must be replaced periodically.
Which periodontal material is used to fill periodontal defects and promote bone regeneration?
- A Alginate impression material
- B Bone graft material
- C Glass ionomer cement
- D Polycarboxylate cement
Correct answer: Bone graft material
Bone graft materials stimulate bone formation in areas of periodontal bone loss. They support regeneration around teeth or implants.
What is the main function of periodontal dressing applied after surgery?
- A To whiten the teeth
- B To reduce plaque formation indefinitely
- C To protect the surgical site and aid healing
- D To control occlusion during healing
Correct answer: To protect the surgical site and aid healing
Periodontal dressings act as a barrier that protects the wound from trauma and irritation. They also help stabilize the surgical area during healing.
Clear orthodontic aligners are primarily made of what material?
- A Polyurethane thermoplastic
- B Cast stainless steel
- C Feldspathic porcelain
- D Zinc oxide eugenol cement
Correct answer: Polyurethane thermoplastic
Clear aligners are made of flexible thermoplastics such as polyurethane. These materials allow tooth movement while maintaining transparency.
Which periodontal instrument is used to measure pocket depth?
- A Scaler
- B Curette
- C Periodontal probe
- D Bone file
Correct answer: Periodontal probe
Periodontal probes measure the depth of gingival sulci and periodontal pockets. This measurement helps assess periodontal disease severity.
Which type of orthodontic retainer is bonded directly to the lingual surfaces of anterior teeth?
- A Hawley retainer
- B Removable vacuum-formed retainer
- C Fixed lingual retainer
- D Functional appliance
Correct answer: Fixed lingual retainer
Fixed lingual retainers consist of a wire bonded to the lingual surfaces of teeth. They prevent relapse while remaining unobtrusive.
What is the primary advantage of using resorbable sutures in periodontal surgery?
- A They increase tissue inflammation
- B They dissolve naturally without removal
- C They are stronger than nonresorbable sutures
- D They do not require sterilization
Correct answer: They dissolve naturally without removal
Resorbable sutures break down naturally in the tissue, eliminating the need for suture removal. They are convenient for many periodontal procedures.
Which orthodontic component provides anchorage to resist unwanted tooth movement?
- A Active elastomeric chains
- B Bands and anchorage devices
- C Steel ligature ties
- D Removable acrylic retainers
Correct answer: Bands and anchorage devices
Bands and TADs provide strong anchorage to control tooth movement. They help orthodontists achieve precise force application.
Periodontal curettes are designed to:
- A Remove only supragingival calculus
- B Excise inflamed gingival tissue
- C Remove subgingival calculus and plane roots
- D Polish coronal enamel surfaces
Correct answer: Remove subgingival calculus and plane roots
Curettes remove calculus from below the gumline and help smooth root surfaces. They are essential periodontal treatment instruments.
Orthodontic separators are used to:
- A Widen the mid-palatal suture
- B Create space for band placement
- C Move teeth into final alignment
- D Polish surfaces before bonding
Correct answer: Create space for band placement
Separators create temporary space between teeth to allow orthodontic bands to fit properly. They are typically placed a few days before banding.
Which type of bone graft is taken directly from the patient's own body?
- A Allograft
- B Xenograft
- C Alloplast
- D Autograft
Correct answer: Autograft
Autografts are harvested from the patient and offer excellent biocompatibility. They have high success rates due to natural compatibility.
Elastomeric chains in orthodontics are used primarily to:
- A Remove supragingival plaque
- B Close spaces with continuous force
- C Hold brackets onto the tooth surface
- D Polish the enamel surface
Correct answer: Close spaces with continuous force
Elastomeric chains produce a continuous pulling force. They are effective in space closure and tooth movement.
Which periodontal material acts as a barrier to prevent epithelial tissue from growing into healing bone defects?
- A Surgical periodontal dressing
- B Guided tissue regeneration membrane
- C Glass ionomer cavity liner
- D Topical fluoride varnish
Correct answer: Guided tissue regeneration membrane
GTR membranes are used to support regeneration by blocking epithelial migration. This allows bone and ligament cells to repopulate the area.
Nickel-titanium coil springs are used in orthodontics to:
- A Increase bracket bond strength
- B Open or close spaces with light force
- C Hold retainers firmly in place
- D Preform the initial archwire
Correct answer: Open or close spaces with light force
NiTi coil springs provide flexible, continuous force, useful in opening or closing spaces. They are versatile components in orthodontic mechanics.
Which dental material is preferred for bonding orthodontic brackets to enamel?
- A Silver dental amalgam
- B Glass ionomer cement
- C Composite resin adhesive
- D Zinc oxide eugenol cement
Correct answer: Composite resin adhesive
Resin-based adhesives provide strong bonding to etched enamel. They are the standard choice for bonding orthodontic brackets.
Periodontal scalers are designed for:
- A Subgingival calculus removal
- B Supragingival calculus removal
- C Cutting soft tissue
- D Measuring furcation involvement
Correct answer: Supragingival calculus removal
Scalers remove calculus above the gumline. Their sharp tips make them unsuitable for subgingival use.
Orthodontic wires that deliver heavy force with minimal flexibility are typically made of:
- A Nickel-titanium
- B Stainless steel
- C Beta-titanium
- D Polycarbonate
Correct answer: Stainless steel
Stainless steel wires provide strong, stiff forces ideal for finishing stages. They offer excellent control of tooth movement.