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
- Explanation
- Unwanted tooth movement (not direction or relapse)
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
- Misplaced
- Solution provide spare set
- Retainer box
- Ease of replacing
- How, where and cost
- Fear of relapse
- Show photos of relapse Vs instructions only, better compliance with those who saw photos Lin 2015
- Create a habit
- Associate with rountine habit e.g. tooth brushing
- Retainer reminder for travel
- Night wear only
- Pyjamas for teeth
- Misplaced
