What to do if a resin bonded bridge becomes loose?
Resin bonded bridges can be a conservative treatment that requires minimal preparation of the teeth adjacent to the pontic space. But sometimes the bridges come loose more frequently than a traditional fixed bridge with full coronal coverage.
what can we do to help reattach a resin bonded bridge that has come loose?
A tip below to try when a bridge comes loose is to add retention holes to the metal wing for extra mechanical retention.
Steps to reattach a resin bonded bridge
1. When the bridge has come loose, drill one to three small holes in the metal wing. Next micro
etch or sandblast the metal wings to clean the surface of any residual glue.
2. Pumice the tooth surface to clean the tooth.
3. Place on the metal wing a priming agent like zprime or silane and air dry.
4. Use phosphoric etch on the tooth and place a bonding adhesive on the tooth, air dry, and light cure.
5. Use your dual cure resin cement on the bridge to bond it to the teeth.
6. When cementing the bridge, let the resin express through the one to three retention holes to create some mechanical retention and go ahead and cure the cement through the holes.
In addition to creating mechanical retention, the holes can help the light to cure more deeply under the metal near the tooth.
Resin bonded bridges are often called Maryland bridges because the University of Maryland developed the electrochemical etching system to prepare the metal wings. They are usually used to replace missing anterior teeth, such as lateral incisor. They can also be used in the posterior.
When to use a resin bonded bridge
Often we could use a resin bonded bridge or a Maryland bridge for a congenitally missing lateral
incisor perhaps after orthodontic treatment.
You might have a young patient who isn’t old enough yet for an implant, and a resin bonded bridge could help restore the space in a conservative manner until the patient is older for an implant.
It also serves as retention of the space after orthodontic treatment and having an option of a resin bonded retainer is a nice fixed option that’s way more convenient than a removable option.
Consideration for design
Another consideration for design. Most commonly we see bridges designed with a metal wings on each side of the pontic. Consider using a cantilever design with a pontic and a single resin bonded wing.
Usually, the tooth debonds on one side first, possibly due to two teeth flexing differently and debonding the glue. And then it can be hard to rebond one wing when the other side is still attached.
It can create a caries risk under the loose metal wing as well. The alternate design could have only one metal wing on the canine and the Pontic for the lateral.
So another design with a circumferential crown and pontic and a resin bonded wing tends to debond on the wing and then can also create a carries risk.
The resin bonded bridge with 2 wings may be the best for ortho retention if we’re planning an implant in the future. But the cantilever can be an option in some instances as well.
You can also increase your retention by placing a rest seat in the tooth prep design, and you can reduce the grey that shows by not extending the metal within two millimetres of an incisal edge.
If a resin bonded bridge becomes loose try mechanical retention holes
So there are indications for resin bonded bridge: create the best design possible, but inevitably, if you encounter a resin bonded bridge that’s become loose, try the mechanical retention holes for extra bond strength.