Exposed microthreads: prognosis for this case?

I wanted to note that alteration of the trajectory of the guided path has been squared away, but I would still appreciate the comments re: the management of the implant with microthreads being exposed. Thank you all again!

I also wanted to add that restorability should not be an issue either as the custom abutment was pre-planned.

Drill deeper and measure the osteotomy prior to placing to placing the implant. Sometimes in dense bone partial tapping is necessary, when this happens take out the implant, remove the guide and redrill to depth with one of the end cutting drills. There is at least 2-3mm bone at the apex. Don't blame the guide angle the osteotomy needed to be drilled deeper. Now you are fooling around with exposed threads after all this planning. I recommend a small flap to assess the bone level at implant placement. I also would have made the implant parallel to both teeth and engaged the cortical plate of the sinus, very stable bone. The sinus will tolerate a small amount of implant.Guides don't place bone, the surgeon still does and unfortunately the surgeon often has to adjust to the situation. This was a minor correction which could have be handled at the placement but it will heal just fine. Simplant is only as good as the surgeon don't get me wrong I like using guides but understand the surgical applications and technique. I hope this post gives you valuable tips for next time.Thanks for posting.

In this case I would have used an osteotome to gain additional length in the bone prep and that would have allowed full insertion. In this case if you use excessive apical pressure you could have blown out the wall of the sinus and possibly torn the membrane. Based on my experience if you are doing two stage and cannot achieve primary Closure then you risking additional bone loss and saucerization from impaction of debris from food and plaque acummulation. Since its a smaller diameter yet appropriate for this site implant likely you will not be able to remove the cover screw with out having the implant come with. Bring the patient in for X rays on a regular basis and if you see bone loss remove it graft it and try again. Best of luck

The angulation looks perfect. It may be better to back out, drill osteotomy to correct depth and replace the implant to the desired level in future cases. This would have been possible here. Hopefully the patient has great oral hygiene and a thick tissue biotype and the area will heal trans-mucosally with minimal bony changes. If their cleaning falters there may be future bone loss with the roughened threads harbouring bacteria and you leave yourself open to criticism.

People are trending to rely on the Surgical guide to "do" the treatment. As you found in this case they can get you much closer to the final result, but there is still no substitute for clinical judgment. Here you had the choice of removing the implant then deepening the channel just slightly, before re-inserting the implant. That would have avoided most of the concerns that you now have. There is another point, bone-level implants with a rough surface up to the platform are becoming very common, almost standard these days. If there are problems such as you describe here then there are always concerns about early contamination of the rough surface. We get around this by avoiding a cover screw and using a 4.0mm gingivaformer, often with a collagen based bone graft up and around the gingivaformer and the flaps are distributed outside it. This avoids the "Danger Zone" of potential contamination at the crest, extends the zone of attached gingiva and reduces surgical interventions.

Implant should have been taken out and osteotomy redrilled to depth. This also could have resulted in engaging the cortical wall of the sinus and improving your primary stability. If you end up with exposed threads do a proper GBR using bone graft and membrane, and try to advance the flap by periosteal releasing to achieve primary closure. With current situation, the prognosis mostly depends on proper hygiene around the neck of implant. Remember that even if you place the implant flush with the bone level you may still get some marginal bone loss during healing stages and at the time of restoration you may have minor thread exposure anyway. Make sure the final restoration is fully cleanable even if this means you have to sacrifice a bit of aesthtics (unlikely to be of concern in 2nd premolar site though).

i think if the case is only completed recently, he can go back in and do the corrections like drilling deeper and use dense bone drill, then place the implant to proper depth. Or use a shorter implant. i think leaving it like that will most likely run into bone loss and poor esthetics because it is tooth 15.

Dear colleagues,out of concern for your valuable time, I will ask you to shift the focus of your commentaries to the management of this case moving forward, instead of focusing on what could have been done intraoperatively. Otherwise, this is the second case I am publishing here and I find everyone's input to be totally Priceless. mark

This implant will most likely integrate without complication and the exposed microthreads will not be an issue. In fact, although microthreads may be exposed, the implant-abutment microgap is in a more ideal position .....so, with leaving the implant supracrestal by 1 mm or so, you may have created a potential problem, but you have simultaneously, yet perhaps inadvertently, eliminated a potential problem. I agree with others that minor correction at the time of surgery is appropriate. Guided surgery is remarkable, but cannot substitute for the experience and skills of the implantologist.

I don't believe that is advisable. It would seem to me that you are just creating a new roughened surface, thus accomplishing nothing. If you really are concerned about this and the surgery was done within the last few weeks, I would consider removing the implant, deepening the osteotomy, and placing another implant. If that is not an option, leave well enough alone.

Unfortunately, taking the implant out is not an option.

Hi. I do not see any problem yet. Bone graft can cover the micro threads . I agree with Mark. If you are facing any exposed threads you can polish it with diamond ( implantoplasty ) suggested by Carl Misch and Khoury. If you will use Ankylos implant you will not face this problem at all. Good luck

Mark, do not prep the microthreads; studies show increased risk of structural failure of the implant head when mechanically altered. Exposed micros are an esthetic failure in some cases and a hygiene challenge in most but not catastrophic; the implant will survive.

As I emphasized earlier you may still get a good soft tissue seal around your implant neck preventing bacterial contamination of the exposed rough surface. So do not rush into implantoplasty. It can be considered if you have persisting peri-implant mucositis around your restored implant despite good plaque control. I'd strongly suggest to do a screw retained crown leaving the options open for further intervention. Although some studies supported implantoplasty some others have not shown any additional benefit stating that the surface that looks polished to the clinician's eyes after implantoplasty, still looks like grand canyon for bacteria!

good work being done here,i disagree with some posters advising for removal and re-drilling deeper, the pt. is not a car at the workshop .subjecting the pt. to more surgeries and drilling and more appointments is not worthy for treating one or tow threads being out of bone level. the simplest and easiest way is to carefully polish the exposed thread with fine diamond bur with good irrigation and consider this polished surface as part of the abutment,and it will be fine .

Dr Mark, At the present time, the only problem/complication with this implant is not with the patient but in your mind. Do not rush to "fix" a problem that does not exist. I agree with the other posters that polishing the implant head is not advisable unless the patient has developed persistent mucositis in this area. Keep in mind that when placing an implant, unless the ridge is perfectly flat, which does not exist unless created by the surgeon, you will always have some micorthreads exposed and some crestal and still others sub crestal. 98% of such implants are still integrating without complication.

I don't know if it is because the series of the latest responses from my dear colleagues are more of "what I wanted to hear", but I like them immensely. Naser seem to understand that implantology is associated with very careful management of the patient's expectations. On a different note: I will have to skip mentioning the name of the implant manufacturer, but the true reason for not complete seating of the implant in this case is the fact that while 3.2X11.5 was planned, and 3.2X11.5 label read on the implant cover, it was actually 3.7X11.5 labeled as 3.2X11.5. If you go back and look at my CT plan and the result, you will see if that implant was narrower by .5mm, it would go where it needs to go, but it got stuck against the cortical plate of the anterior wall of the sinus because of the width that was not accounted for, and the last thing I wanted to do intraoperatively is to start making additional osteotomies to correct the position and I had to make the tough decision to leave the implant where it is. So, these things happen too.

I understand the responses are coming from practitioners from all over the world, and each of you accustomed to different socio-legal environment. Mine is such that the ratio of dentist to personal injury attorney is about 1:5 and all those guys are looking for the ways to be busy, hence here we have to measure 10 times before we cut. And your responses are extremely helpful and stimulating regardless whether they will result in any corrective action on my part or not - I have been learning a lot from you, guys, and your responses make me go back and do a lot of searching and reading.

Redoing an implant or correcting a poor placement is not malpractice but good care. Not taking advice when one knows how to correct it is suspect. When one has enough misadventures the business model may change, it is better to remain in ones skill set less time effort and money used to correct things. Also having to stock all this material and equipment along with the training involved is a loss leader.In the major US cities one may be held to the standard of an OMS with implants but it depends on the attorney. Implant placement is always a challenge I like a team approach and I trust and depend on my restorative colleagues you guys are the best!!!

CRS, I think the basic premise upon which this forum is based - there are no "stupid" questions. And I think those of us who set aside the fear of looking vulnerable should deserve little credit and not criticism. I've been thoroughly enjoying the parts of your comments that contain constructive criticism, but I don't feel the same about politically loaded ones hinting to the eternal question "Who should be placing implants ,GP or OMFS."

Dear CRS, This question and commentary just took a turn for the worse after your politically loaded commentary. The question and comments all had great ideas and wonderful sharing until your comment about being "held to the standard of the OMS". While I am sure that you and many of your OMS colleauges have great skills and knowledge base, I can assure you it is often the case that the standard of care when it comes to implant placement by the OMS is a very sorry standard indeed! Let's continue the sharing and learning instead of lowering the level of the discourse

Jonathan, I would like to add that the standard statement was from a malpractice attorney from a large risk management company seminar so I am just passing it on. Actually I feel that one statement does not make a politically loaded comment nor does it lower the level of the discourse and my advice falls in line with the other posters. Not sure of your reaction, I enjoy interacting in a non defensive way with my implant colleagues. Not meant to have you take it personally, but thanks for sharing the viewpoint. It just blew me away that it took so long for the poster to reveal the size difference could have had the answer sooner to the puzzle no shame here! I personally feel it is better to be honest in clinical management vs just trying to make the poster feel better but I can do that also, I personally would rather have the former. Thanks for reading, like the feistiness Go wildcats! Hope that was the right website!

CRS, thank you for taking time with your response. I owe you the same, hence lets break things down: 1. Intraoperative decision making. As I have mentioned in the outset, the decision not to make any corrections was very solid, based on the limited amount of bone to play with as well as the poor quality of the bone. So ,it was well weighed decision to leave implant where it is and to deal with couple of microthreads exposed. 2. "Guide was bad". The guide was perfect. If indeed the implant that I had was 3.2mm ( as label indicated ) and not 3.7mm, I would place that 3.2 where it belongs and we would probably not talk about this right now. But the implant was mislabeled. 3. Mislabled implant. 3.7 and 3.2 both look quite skinny. I have had remained puzzled as to why the implant did not go all the way for 24 hours. During this time, a friend of mine pointed that the implant looks too big for 3.2mm. I did not react to that comment right away but when I went back and measured this implant on the digital radiograph, I have discovered that it was actually 3.7mm.... As soon as I did that, things fell into place as to why implant did not go all the way. I have been in contact with manufacturer re this already. So, at the time of the placement and for 24 hours afterwards I was convinced that I placed 3.2 and the "guided was wrong". Once I measured the implant on the pic, things fell into place for me. And once again, I did not feel like it was appropriate for me to back out the implant and try to trill more mesial: I was risking to either get into sinus or damage the root of canine trying to get into the tight space doing it without guide. Hence my decision. I hope this clears things up and we can continue our productive communication. Mark.

CSR, I apologize for perhaps overreacting to your comments. The reason for this is that I have been following this website for some years now and have always enjoyed the sharing, learning, and commentary. However, there always seems to be a few individuals that, in one way or another, through innunedo, suggestion, or direct attack, display pomposity or an agenda inconsistent with the purpose of the site...which is sharing and learning, without regard to whether one has little or much experience, a GP or OMFS, etc. Anyway please accept my apologies. Dr Dankowski, thank you for posting and interesting case and best of luck with your decision making process.

Understand your explanation, I would have ordered the right replacement sized implant and placed it the following week (prior to osteointegration), the patient would have appreciated it. I like to have one size smaller/larger or shorter/longer in stock in case the bone is poor quality or there is a surprise at surgery, it happens, and it is nice to be prepared. With the original narrower implant might be a better restoration I would replace it undermine my flap and close it primarily. This is a simple error to fix since the osteotomy is already drilled. It is your judgement call since I was not there and I can respect that. Hopefully the advice was helpful the intra operative decision making is to check the implant size by using a labeled drill for comparison, I keep an endo ruler on the tray. I actually got a notice from Nobel on an labeling issue which I thought was odd. Thanks for reading.

These things happen. I use a mirror handle that has mm. markings (Miltex). Anything could of happened from the burs being out of sequence (boley gauge in set up). CRS gave some good advice. This is part of the learning curve. These things can happen to any of us. I also recommend a magnifying glass to read the markings. The manufacturers are not always user friendly. Take it out and use a slightly wider and shorter implant. You should be fine!

Thank you all! Will be taking implant out.

Mislabelings happen.... . You allways walk alone meeting an attorney on the side of your counterpart. Therefore it is important to meet collegues and their oppinions- although we do not have to share the oppinion or the therapeutical approach. Many ways lead to Rome and manyfolding obstacles can be met. Sometimes we are to be blamed, sometimes others. We should remember that and not become collegoides- though we are in competition.

From the radiographs provided, the implant is well placed, the exposed microthreads that may be supracrestal are easily concealed by making a longer crown....preferably a cementable situation...the technician can do the wax up over the threads....the temporary cement will seal them.... end of problem..... forget about the lawyers....tell them there is more money in chasing ambulances, than running after talented dentists who like to do implants! Gerald Rudick dds Montreal

Gerald, thats a new spin the approach to this case. Very interesting. My concern is the management of soft tissue while waiting for stage two. It could be too early to draw conclusions but on first post op exam soft tissue did not look like it liked microthreads too much

Pardon typos. Using my cell.

Gerald brings up a good point. This happens of the topography of the buccal bone. If the gingival is thick enough, it's not a problem. Just ad some particulate such as OsteoGen at the time of placement. If this occurs at the time of uncovering and it's not severe, then consider prepping lightly down on the implant. A feather or slight chamfer finish line will not greatly weaken the implant. Misch mentions this in his very first text.

When your osteotomy was redirected you hit the cortical plate which prevented you getting to full depth. The reason you lost retention with your implant was that you continued to push either the osetotomy further or you tried to force the implant to depth and either could cause the osteotomy to enlarge The next size implant and shorter would fix this