When to use which implant overdenture attachments?
ERA=vertical resilient better for implants
Locator=rotational better for teeth
Where implant is at help decide ERA vs locator
Best location for 2 implant lower overdenture is lateral incisor and then canine. However, this list will help with those implant assisted partial dentures.
- Molar want rotation so Locator
- Canine can go either way
- PM worst area want ERA, like a teeter tooter
- Anterior can be either (square jaw=locator or v shaped=ERA think of as similar to PM in terms of rocking forward and back)
A clinician is likely to use the standard Locator attachments when treating parallel implants. According to Nadir that is wrong and we should use ERA.
O-Ring ball, ERA, Locator, Rhein 83, GPS are the most common US used brands.
Bredent off of canine crown Bredent VKS attachments DT thread Precision attachments, intra/extracoronal attachments with max RPD treatment plan
For the clinician who desires the greatest degree of rotational freedom, the ORS with the least retentive component is the attachment of choice. 1
O-rings from OCO Bio Howard C. loves and uses a lot. Ceka and O-ring do have the highest rate of implant lost though according to Ghiasi 2021 IJP review.
Retention Hader clip and ERAs>ERA w or without bar>Hader clip. so Hader by self no good and bar no different if just ERA Williams 2001 JPD
Ball v. locator pt like same locator more maintenance ball more vertical room
Different implant overdenture attachments by type
Bar and clip system
Some have a spacer that allows for some vertical resiliency. There are several types of bars the clips can attach to. A milled bar is more for the implant supported overdenture. A resilient bar, like the Hadar bar, has a single axis of rotation. There are also various Dolder bars that allow varying degrees of movement.
Studs
Locators, ERAs, and balls are all examples of studs and these are probably the most popular attachment types in the US. The other studs are better than ball attachments according to the lit review by Girundi JPD 2024.
Telescopic copings of both right and nonrigid versions.
Several companies have their own lines of these and the term “telescopic” varies on who one speaks with.
Magnetic attachment systems
These are not common. We have never seen one. They are weak systems that get weaker over time.
Repairs and fixes of implant overdenture attachments
If need remove locator housing. Heat up a allen wrench of mirror handle (red hot) and insert into empty housings. It may take two attempts and light cured material doesn’t soften like like acrylic but breaks down and crumbles and takes a few extra attempts. But when they are ready you can walk the housings out with no damage to the housings. Here is a short clip of how to do it.
Need an angle correction on your locator? If the inserts are wearing fast non-divergence could be your issue.
If you have the space then an angled MUA is a great option. Just use the angled MUA then a locator abutment collar.
Overly divergent implants can use kerator DT post says can correct up to 20 degrees.
Another option is to keep the black inserts in or use the extended range inserts for the Locator system. You may also want to try Blue Sky Bio’s Super Snap system instead. They are made of a material that holds up better in non-parallel situations.
Someone on there recommended screw retained abutment with locator on top BUT this might happen if cast top of locator only
There are probably multiple option now for labs to mill a correction coping and get it attached to a parallel locator. T:LOC custom is one example of this. They also make custom MUA. Staumann has the Novaloc system with angle correction and PEEK inserts, which might be better than nylon. Yue JPD 2020
Seating the locator
Use the torque tools to finish seating but to start use the LOCATOR Core Tool End.
Locators on a bar
Locators on bar by Uwe Mohr
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| Making sure parallel |
Kit repair of ball
Overdenture attachments on a natural tooth
Locator on coping by holden
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| Broken (probably because lab sectioned original thread and cast just the top to coping) |
Custom coping in RCT tooth root
- Prepare canal with Zest pilot drill
- Use spot face diamond drill and ensure below surface 360 degrees
- Check fit of cast to female in access
- Attach cast to female to plastic parallel post and place at desired angle.
- Lubricate internal post space of canal with vaseline
- GC Pattern resin into the coronal space of root and seat cast to female with post at desired angle
- Remove several times prior setting to ensure draw
- Add additional resin as needed
At this point 1 of 2 things is done
- If making cast locator to pick up in existing prosthesis then just send acrylic/post/cast-to female assembly to lab to fabricate custom coping
- If making new prosthesis can do pick-up impression to capture when taking final impression for denture.
Either way cement female coping with Relyx luting and pick up in office. Be sure lab has male parts and left room like this. March 12
Locator dental implants
The kit is really nice and the implants have a nice design.
