Surgical guide stent to install the implants: feedback?

Just because you use a guide does not guarantee you perfect results. Guides can me off an average of a mm. Combine the 2 and you have 2 mm that you can be off, out of the 3 mm that they were probably designed to be spaced. Also take into account any overlapping that could have happened in the radiograph. Those implants do look close, and may be hard to restore. Did you take radiographs with the pilot drill?

My comments assume that his was done by computer guided implant surgery, and not with a lab derived suckdown. As noted, if the radiographic angulation is not off, the implants are too close together and too distant from the adjacent natural tooth. There are a number of potential causes of this type of implant positional error: 1. Planning error - there could have been an error at this level due to inadequate planning data. Did you have visualization of the soft tissue and teeth, in addition to the bone when the case was planned? Conceptually, was the inter-implant spacing appropriate to the diameter of the implants used or based on smaller diameter implants? Ideally, this case could have been planned using virtual abutments which approximate the mesial-distal dimension of the future teeth. If the plan is done by this method, the mesial-distal positioning would have been ideal. The buccal-lingual position is not mentioned, but would be ideal if data from articulated models were incorporated into the planning software. There are a variety of methods in data acquisition, which allow one to precisely determine future tooth position in the software. 2. Who planned the case - if one is inexperienced, it is not that difficult to place the virtual implants in the wrong location in the software. 3. Because the implants are parallel, it seem less likely that the 1 mm error due to movement of the drill tip caused the error. It should be noted that this deviation varies from guide system to guide system and that some guide systems have virtually eliminated this deviation. 4. Guided surgery is a funny thing. Sometimes, just because we have a guide, we leave our brain at the door and just go with the guide when we do the surgery. It is essential to build in quality control steps when doing implant surgery, and especially when doing guided surgery. This allows detection and correction of positional errors before one is at the point of no return. For example, place the guide, and prepare a 2 mm deep pilot hole. Remove the guide and visually determine if it is correctly positioned, If it is, then complete the case with the guide. If not, you are now able to reposition the pilot hole and do the case free hand. Bottom line is to validate and verify the crestal entry point position and trajectory before completing the osteotomy.

This was a planning error. In the future, you must understand and approve the relationship between the planned restorations and the sites chosen for implant placement. Start with the end in mind - set denture teeth in wax on a model and use it to optimize the location of the implants. Ideally you would scan it and merge the STL file with your CBCT image for complete control; you could also just use your mind's eye to relate the model to the scan (simple cases, experienced operators). Only when you are certain that the placement of your virtual implants is in harmony with the restorative plan should you allow a surgical guide to be fabricated. As for what to do now - you can either restore it with the implants too close together, or you can remove and replace one implant. If you use a platform switched abutment and leave a good sized embrasure for access to clean between them, I think you will be OK. Try a small interdental brush dipped in Peridex for cleaning the site; maybe use a WaterPik if pt has limited motor skills. Good luck.

Can't evaluate much based on this film.

This is a perfect example how some of us are relying too much on technology, and not going back to the basic roots of dentistry as both an art and a science. In a rather straight forward situation such as this, it would have been perfectly acceptable to do this case free hand, drill preliminary pilot holes and place measuring pins in the holes and take an xray to get an idea of the alignment........ very often if the alignment does not appear acceptable, it is possible to realign at this stage........ Cone Beam technology is great, but so is skill , care and judgment. Gerry Rudick DDS 1966 " a Montreal dentist from the old school".

Love it Gerry ......... I always work on the notion that I do not know and check everything even when using guided ! Cars can drive themselves now but I still would like a hand on the wheel... Peter

I would take another orthograde PA, if still the same distance between 2 implants , then I would remove the first from right and replace. Think forensic and legal consequences.

I would like to know what system was used to design the guide ? Most now have built in fail safes in which they would have never been to close without you turning it off .