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Retention – science, clinical tips and comedy disaster Simon Littlewood. BOC 2021.September 22nd 2021. Episode 129

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Hosted by
Farooq Ahmed

Join me for Simon’s lecture looking at fixed and removable retainers and recent research Simon has been involved with.

 

Bonded retainers

 

  • Failure 12-50% Kucera 2021
    • Failure of wire
    • Failure adhesion composite – enamel
  • Problems
    • Unwanted tooth movement (not direction or relapse)
      • Possibly not passive or distorted wire Abudiak 2011
      • 1:100 show unwanted tooth movement
        • Explanation
          • Unravelling of twistflex
          • Forces

 

Material options alternatives to twist-flex

  • CAD/CAM NiTi Memotain
    • Shape memory
    • Precision made – lazer cut
    • Claimed ideal upper arch
      • Scan occlusion
      • Technician design retainer
    • £95 per retainer
  • Ortho-flex-tech Direct bonded
    • Chain SS
    • Bond directly
    • Cannot exert active forces

 

Study: Memotain Vs Orth Flex-Tech

Aims: Memotain Vs Ortho flex-tech

Method:

  • RCT
  • Multicentre
  • No removable retainers
  • Upper and lower BR

Results

  • Trial terminated at 6 months
  • Memotain
    • Upper 50% failure
    • Lower 35% failure
    • Spaces open up
      • Failure between composite and wire
      • Not chemical bond – physical bond
      • Memotain electropolished – reduced physical bond
    • FlexTech
      • Lower failure 31%
    • Hazard ratio 3 x more likely failure Memotain Vs FlexTech
    • Stability
      • No significant difference – study underpowered
      • 2 patients re-treat in Memotain
    • Patient satisfaction
      • Patients satisfied with both retainers

 

Conclusion

  • Problems occur usually within 1st month
  • NiTi – question if the right material

 

Future research

  • Custom bend wire retainer: 25% failure rate Shim 2021

 

 

Removable retainers

Fixed Vs removable retainers Dalia- Al Moghrabi 2018

  • No significant difference at 2 years
  • 67% not wear VFR at 4 years

 

Qualitative study – perception of orthodontic retainers and factors affecting adherence

  • Dalia- AlMoghrabi 2019
  • 6 tips of removable appliances
    1. Misplaced
      • Solution provide spare set
      • Retainer box
    2. Ease of replacing
      • How, where and cost
    3. Fear of relapse
      • Show photos of relapse Vs instructions only, better compliance with those who saw photos Lin 2015
    4. Create a habit
      • Associate with rountine habit e.g. tooth brushing
    5. Retainer reminder for travel
    6. Night wear only
      • Pyjamas for teeth

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