Can implants be immediately loaded with a Locator retained denture?

Why don't you use the cupid implants as temporary support while the new implants healed? I would be concerned loading any implant with locators immediately Also you might want to see if you can determine why the implants are loosing facial bone Could be placement was wrong angulation or too far buccal but also could be angulation issues with the 4 implants. There are some guide pins that you can place on the locators to tell you their angulation If you are opposing natural dentition, what is left? This could be the cause of the problem with bone loss - would be great to see what it is opposing if natural teeth. an upper denture would not generally tend to put the kind of pressure on the system as natural teeth. You cannot allow natural teeth to have lateral forces on this type of appliance and I think that would take some great occlusal skills to create the kind of function you need here . If you have naturally teeth upstairs I would be careful with this. Placing the implants at the lateral position will likely not allow a straight line of occlusal forces over the implants and since the posterior plane will be outside of the support you will have tipping forces . Remember that locators are not made to rotate and have no compression built in -they are only made for vertical support .JMHO

Just going by simple mechanical principles, the failure of implants in both canine position is indicative that most likely stress is the cause of failure (bilateral failure). In the principle of All on Four two of the implants are at an angle and the extension of the restoration should be about 1.5 times the A-P distance. The canine most likely had more available bone than the laterals have and the suggestion is to avoid duplicating the failure. Perhaps grafting the canine area and placing implants in the same location and adding two in a more anterior area, centrals or laterals would be a solution. The available scan could provide some voluble information to determine further steps.

The quick answer is not to immediately load the implants. Locator retained dentures place considerable stress on implants in the upwards direction when the denture is being removed. This is the primary stress problem immediate loading will generate. However if all implants/locators are not parallel then there will also be lateral forces at play on insertion and withdrawal of the denture, and such forces will have a very negative effect. Bill McFatter’s suggestion is one I would also recommend. Use the existing implants initially and place extra implants using a two stage technic and exposure after they have integrated. Further, Paul is also offering good advice in regards to positioning of the new implants and also determining why the canine implants have failed. However another consideration would be to use a bar retained over denture next time. It would require extra treatment planning to co-ordinate the timing of removal and replacement surgery, healing and construction, but the occlusal load would be better distributed and also the laboratory can make sure the locator retainers on the bar are parallel. I would expect a better prognosis for long term success if you placed a bar – preferably on 5 or 6 implants. So as I mentioned, you would need to carefully consider how to go about achieving this.

How urgently do all of the implants need to be removed? My first choice would be place new implants, wait for integration and then remove the failing fixtures. If two of the existing implants could be retained during the healing process we could avoid the cross your fingers and hope it works step. After the new implants have integrated, I may consider done regeneration around the existing fixtures (remove Locator, place cover screw, flap, RotoBrush, graft, membrane, suture). Preserving two of the four could be consider a success.

I do immediate loaded locator dentures with at least 4-6 implants all the time. I place the least retentive housings and I do not have the patient remove it for at least a month. Like you have already stated there is too much stress to be taking it in and out during integration.