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Orthodontics > Vacuum Formed Retainers > Flashcards

Flashcards in Vacuum Formed Retainers Deck (14)
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1
Q

What is the rationale for maintaining teeth in their treated position?

A

Allow for reorganisation of gingival and periodontal tissues

  • Minimise changes from growth
  • Permit neuromuscular adaptation to the corrected position
  • Maintain teeth in unstable positions (sometimes)
2
Q

What factors should be considered in choice of post treatment retainer?

A
  • Pre-treatment situation
  • End of treatment result
  • Post treatment growth potential
  • Oral hygiene
  • Aesthetic requirements
  • Patient compliance
  • Ease of retainer fabrication
  • Durability
  • Cost Effectiveness
3
Q

What types of machines can be used to manufacture VFR’s?

A
  • Pressure machine: “superior”, force heat softened plastic over end of treatment plaster mould using positive pressure
  • Vacuum machine: adapt heat softened plastic to mould by negative pressure
4
Q

What are the two materials used for VFR’s?

A
  • Essix type ‘A’ co-polyester: More aesthetic but tend to fracture more easily
  • Essix type ‘C+’ polypropylene or ethylene co-polymer: More resilient but less retentive
5
Q

What is the most common extension of VFR margins?

A

1-2mm buccal and 3-4mm lingual to gingival margins

6
Q

How is a VFR retained?

A

Undercuts gingival to the contact points of the teeth

7
Q

How can a VFR be adjusted?

A

Increasing or reducing depth of undercuts by scissors or greenstone slow speed

8
Q

What can be used to clean a VFR? Why is toothpaste not recommended?

A

Toothpaste can dull appearance

Regular cleaning with soapy cotton tip swap and/or propriety cleaning agent is recommended

9
Q

What are some advantages of a VFR?

A
  • Aesthetic
  • Patient comfort and acceptability
  • Speed, ease and low cost of manufacturing
10
Q

What are some disadvantages of a VFR?

A
  • Compromised retention if hyperplastic gingiva, poor oral hygiene, or spaced dentition
  • Loss, breakage, poor wear resistance (concern with bruxism)
  • Possible inability to maintain expanded arch due to lack of rigidity
  • Inhibits any desired vertical ‘settling in’ of occlusion subsequent to treatment
  • Potential for demin and poor gingival health if detrimental dietary lifestyle (e.g. frequent soft/fizzy drink) while retainers worn
  • Reliance of patient compliance as VFR removable
11
Q

Does the evidence suggest that there is significant difference between full time and part time wear of VFR’s?

A

No, although patient factors such as severe crowding may warant alternative wear protocol

12
Q

What is used to measure incisor regularity and also commonly used to assess relapse?

A

Little’s Irregularity Index

13
Q

What does the evidence suggest the effectiveness of a VFR is compared to a Hawley and Bonded Retainer?

A
  • At least as effective as Hawley in maintaining post-treatment stability
  • Less effective than BR at maintaining lower incisor alignment, but no significant difference in upper incisors
14
Q

What does the evidence suggest in terms of the problems related to a VFR is compared to a Hawley and Bonded Retainer?

A
  • More problems in VFR compared to BR
  • Less problems in VFR compared to Hawley
  • VFR’s have no detrimental effect on dental and periodontal health and more cost effective than Hawley