Important pearls for in house aligners. Renato Martins
Join me as I summarise Renato Martins great lecture giving pearls for aligner use regardless of system.
Conclusion
1. Stage tooth movement if not favourable for aligners
2. Overcorrection
3. Attachment surface – always use bevel edges
4. Check occlusion if lack of tracking
Founder of e-motion: aligner company
· Software recommendation Archform
Renato described difference movements with aligners and his tips on achieving them.
1. Synergistic movement
§ Predictable movement
§ E.g. extrusion and retroclination
2. Stand alone movement
§ More challenging
§ Staging movement increases predictability
§ Solution 1 – change to synergistic movement:
· Rotation LL1:
· Split rotation correction with
o ½ proclination and ½ rotation
o ½ bring back in and ½ rotation
§ Solution 2 – Change to antagonistic movement
· Not consistent with desired movement
§ i.e. distalise canine, can cause distal rotation
§ Antagonic: create counter moment to prevent unwanted movement
§ Antagonic movements are difficult simultaneously
§ Solution
· Stage movement
o Distalise and rotate
o Then counter rotate to correct
3. Intrusion
· 2 stage intrusion
o Canines intrude initially
o Then intrude 2-2
4. Rotation
· Overcorrection
· Overcorrect rotation by 30-50%, greater rotation, greater overcorrection
5. Attachment design
· Always use bevel surface for active surface
o For example extrusion
o 90 degree active surface: when plastic engages with attachment the aligner doesn’t fit fully and the cervical aspect of the aligner loses contact / adaptation, aligner pivots on the active surface due to it being steep / 90 degrees
o Bevelled active surface: larger surface of active engagement, therefore less deformation and pivoting, better adaptation at the cervical aspect
o Same as NiTi we focus on the final wire shape, not necessarily the elastic deformation during alignment, same with attachments
Clinical
· Flowable composite: Ensure highly filled, if not can abrade
· IPR: Imprecision in scan / impression, segmenting of teeth = Less than 0.1mm than planned due to imprecision in set up
· Not tracking: Check occlusal contact as heavy contact can prevent tooth movement, as well as interproximal heavy contact
