Prosthodontic Solutions

A case referred to me back in 2018, when I use to take pictures of everything.

A great example of the limitations of 2D imaging and a demonstration of the fact that implants do not in fact 'preserve' bone.

This situation is quite common in the mandibular posterior. Typically seen in thin alveolar/gingiva anatomy patients. This astra fixture was placed by a very good oral surgeon. I was not involved with the planning or details of placement. It was an immediately placed implant. However, what I was told from this oral surgeon I trust, was that a complete alveolar socket/housing was present, the gap between the implant and buccal plate was grafted, and the implant platform was placed at the appropriate 3mm distance sub-crestal.

Notice the anatomy distal to site #30. The entire quadrant appears as it would for typical thin anatomy post-extraction residual ridge resorption. Grafting, especially with the limited amount of gingiva present, would have been futile (I'll show some of those in the future btw). If the plan was delayed placement, there would likely not have been an implant placed at all because of the amount of residual ridge resorption and challenges inherent in fighting against a patients underlying genotype/phenotype.

So while this implant was integrated and looks 'good' on a radiograph, the majority of the buccal surface is only covered with a thin layer of mucosa. Notice how close an impression coping is to the buccal contour. That was likely soon the recede and expose the buccal threads, leading to mucocitis and other long-term concerns.

7

Remember Nobel Perfect implants? When I was in my grad program, they were all the rage. Massive marketing push from Nobel at the time. A mere ten years later the implant was discontinued. Parts are now terribly difficult to come by.

This is a great example of how implant companies have all but forgotten clinical trials for new designs/features. Clinical providers become the testers. So buyer beware on any new implant designs.

This 'Perfect' implant was present and healthy previous to when I did a reconstruction for the consequences of on-going periodontal disease. it would have been easier and more predictable to have this space restored with a pontic/FPD.

About 10 years after the reconstruction, despite constant maintenance effort by the patient, the implant became actively diseased. Despite debridements (note cut back rough surface) the adjacent teeth were put at risk. The implant was recently removed due to chronic active inflammation.

Now I can make her that FPD - which should have been the provided treatment when #9 was originally lost.

Natural tooth FPD complication rates are SIGNIFICANTLY lower than the complication rates for dental implant replacements. It's not really that close when you actually collate the research and manage the implant biases.

6

Dug out this image from a referred Hybrid failure case I treated in 2011. Thought it made sense considering the case from my last two posts.

This is always a frontline way to try and remove broken screw ends. The keys are: go slow, be patient, use magnification. Ideally, find a flat edge of the broken screw. Use the explorer tip to push counter to the threads (typically counter clockwise). If you see any movement at all, that’s a sign you’ll be able to unscrew the piece without more aggressive (riskier) methods.

Luckily I’m not having to do this for the many successful conventional complete denture cases we treat.

Remember: With only rare exception, patients that say they ‘want implants’ are actually asking for ‘teeth that work.’

Treatment plan accordingly.

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Part II: Once you've removed these failed hybrids, you can finally confirm what you're dealing with. In most instances, what happens next is dependent on 1. patience, 2. having the necessary equipment/supplies in office, and 3. patient factors.

Point 1. Handling this emergency took me 2.5 dedicated (meaning my full attention) 'in the chair' hours. If you choose to help these people you better not be in a rush. Since the vast majority of these prostheses are poorly made or fitting, the priority is on trying to save the implants, if possible. This gives the patient choices once reconstructive options are discussed.

Point 2. If you're someone who has to call the implant rep for help/advice, don't take these emergencies. Our 'tackle box' of implant drivers now includes over 70 different sizes and types. You never know what implant/screw is actually there until you see/feel them. I also recommend magnification for the broken screw removal steps.

Point 3. The patient you are helping needs to be fully informed. This is for their knowledge/safety but also for yours as the provider. These are never good situations. Many patients don't really understand how difficult/bad a situation they are in. Those that do are also usually emotionally distraught if not downright angry. It's tempting to promise to be a hero. Don't. Give them doom and gloom. That way, if it turns out even half way good, you're the savior. Lastly, don't attempt to help unless you are REALLY SURE of what you are doing.

This topic is a half day lecture, so I'm only going to give basic highlights...

A. Implant #20, as noted was mobile. I was able to back it out uneventfully. I removed the loose granulation tissue within the osteotomy and sealed the thoroughly cleaned screw access channel/interface on the hybrid at this site.
B. The prosthetic screw in the straight multi-unit abutment at site #27 was found to be still slightly mobile (miracle #1). Under magnification the broken screw piece was backed out leaving a useable abutment. I confirmed at this point I was dealing with a Branemark (Nobel) Multi-unit abutment clone. These were all NeoDent implants.
C. The prosthetic screw in the angulated MU abutment for implant #29 was found NOT mobile. After various attempts at removal I aborted prosthetic screw removal and instead confirmed that the abutment being used on implant #29 was the same as the abutment that was used on the failed implant #20. I therefore removed the abutment from #29 and replaced it with the abutment that was on the failed implant #20 (miracle #2). He now had useable abutments at #27 and 29.
D. The now buried implant at site #22 was accessed by removing the overgrown soft tissue. BTW, I confirmed that it was PVS impression material encapsulated within the peripheral gingiva of this implant. The PVS was removed. Once I had access and visualization of the broken abutment screw I went through my usual sequence of screw removal techniques. With a little luck I was able to get the piece of the screw to move (miracle #3). However, when they are so deep within the implant they are difficult to actually retrieve. I had fun using a pic-it-stick to grab the unscrewed/loose piece and remove it.
E. Now I had a usable implant at site #22. Problem was that the abutment was broken. I actually chose to use the broken abutment in it's original place. This implant design has a long internal connection zone. This means that despite not engaging with a screw, the abutment still sat fairly stable within the implant. So from a support perspective, the hybrid had three implants.
F. The two new active prosthetic screws at #27 and 29 (I keep spares of these in stock for the primary US brands) are enough to retain the hybrid while the three abutments/implants are enough to TEMPORARILY keep the hybrid in place. I did use a prosthetic screw for the abutment at implant #22 to maximize the lateral stability/support provided by the broken abutment.

Obviously, the left posterior segment was heavily reduced to take that side out of occlusion (by 2+ mm's). So yes, this guy left with the hybrid in. While everyone was very 'happy' once it was back on, everyone also understands this hybrid's days are numbered and a definitive plan is now needed before things get even worse.

The patient, having seen how we can handle these issues, now rightly trusts us to try and help him with the next step. Whatever that may be.

Thank you for the interest. My main lesson here is that implant complications are common, difficult, costly, and require specialty level skill. This is a primary reason implant treatments should not be considered without full disclosure of risk. Conventional treatments tend to be safer and are generally equally effective. These need to be given their just place in the treatment planning algorithm's.

4 part II

Part 1: Despite saying I would post on past cases it seems the current run of emergencies are more than willing to share their experiences and it makes my point that implant complications are common and becoming more so.

I met a nice man yesterday who was referred from another office because his mandibular Hybrid was loose and it hurt. He had both arches treated in Mexico in 2020 and had not been to a dentist since. He said his symptoms began about 3 months ago.

Our initial screening panorex showed likely implant failure at site #20. The referring DDS told us that the prosthetic screws on #27 and 29 were fractured off and stuck in the abutments. As can also be seen on the panorex, the abutment for implant #22 was also broken. This one was removed and not replaced by the referring DDS. The screw remnant can be seen still within the implant.

The patient was made aware that the failed implant needed to be removed immediately and that it was very unlikely he would be able to use the hybrid, even temporarily. As seen in the images, upon removal, the broken prosthetic screws in #27 and 29 were confirmed. Implant #20 was also confirmed as mobile (failed). The blanching of the tissue in the photograph is from the anesthetic. He needed to be anesthetized due to the pain associated with the failed/infected fixture. Interestingly, there were several pieces of impression material embedded within the soft tissue around the #22 area. This was likely left from the fabrication procedures in 2020.

Now what?

I'll post how I dealt with this in a few days.

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All too common...

Emergency visit yesterday when this patient had pain and a loose maxillary hybrid. This hybrid was made the previous year by an implant clinic in Las Vegas. Their website states "99% of our patients never have to come back for follow-up after our one day procedure."

After accessing the abutments it was apparent this implant at site #8 had failed and was the source of the pain. This was removed to allow the tissue to heal.

This situation was poorly planned from the start and demonstrates the HIGH risk of implant failure and complications. Specific to this situation: large anterior cantilever, lack of posterior contact, excessive anterior contact (on the cantilever), active periodontal disease (mandibular teeth), active caries (mandibular teeth), and limited interocclusal space just to name the obvious.

A large investment now lost and a more difficult situation to deal with moving forward. Although I am able to temporarily replace the hybrid, it will come loose again with more issues to follow.

Thank you to the patient for allowing me to share this. See less