Appliance repairs.
Most appliance breakages are repairable if the pieces are complete and the cause is identified. A repair that ignores the cause produces the same breakage again.
Common breakages
Fractured acrylic baseplates, usually along a line of weakness where the material was thin or notched around a frenum. Broken or distorted clasps and labial bows. Debonded or fractured wire components on fixed appliances.
For thermoformed retainers, cracking or tearing at a trim line, and permanent distortion from heat — the latter is not repairable and the appliance needs remaking.
Send all fragments including small ones. A missing piece means the relationship has to be reconstructed rather than reassembled.
Diagnose before repairing
An appliance that has broken more than once in the same place is reporting something. A baseplate fracturing repeatedly usually means it is flexing, which means the fit has deteriorated.
A clasp that keeps breaking is often engaging too deep an undercut, or being flexed excessively on insertion and removal — which may be a design issue or may be how the patient handles it.
Where the underlying cause is not addressed, the repair buys time rather than solving anything.
Do not attempt a temporary fix
Adhesive applied to a fractured acrylic edge contaminates the surface and frequently makes an accurate repair impossible, turning a repair into a remake.
The same applies to attempting to reshape a distorted clear retainer with heat. Thermoformed material that has distorted cannot be restored.
Send it as it is, with a description of what happened.
When a remake is the better answer
Where an appliance has been repaired several times, where the acrylic has become thin or porous, or where the teeth have moved since it was made.
Remaking to an old model reproduces a position the teeth may no longer occupy. If the patient reports the appliance has felt tight or has not been worn for a period, take a new record rather than assuming.
Say what has happened and we will tell you whether a repair is worth doing.
Records for a repair
The appliance and all fragments. A description of how it broke and whether it has broken before. Whether the patient has been wearing it consistently.
Where the appliance no longer seats, a new impression or scan is needed. A repair to an appliance that does not fit produces something that still does not fit.
Note whether the patient can be without it, because that changes how the case is handled at this end.
When the patient cannot be without it
A retainer is holding a result, and a patient without one for a fortnight may find it no longer seats when it comes back.
Where that is a risk, say so when you send the appliance. Depending on the case, the answer may be to take a fresh record at the same time so a replacement can be made if the repaired appliance no longer fits.
Advise the patient to keep wearing any other retention they have, and to contact the practice if the teeth feel like they are shifting rather than waiting for the review.
Prevention
Give patients written care instructions with every appliance, including the point about heat — a dishwasher, hot water or a car dashboard distorts acrylic and thermoformed material permanently.
Advise them to bring the appliance to every review appointment. Wear and early cracking are visible before they become breakages.
See appliance care for guidance worth handing out.
More in Orthodontic Laboratory
Send a case
Digital scans and conventional impressions are both accepted. Cases move by UPS and Purolator, and Fairmont works with practices throughout British Columbia and across Canada.