Bicon Abutments Keep Popping Out: What Can I Do?
I have placed several hundred Bicon implants during the past 3 years – all of them without major problems. But now, a patient of mine keeps coming back to my clinic because her 2 Bicon abutments/crowns keep falling out alternatingly.
I had placed these 2 Bicon implants in the sites for #13 and 14. Healing and integration was perfect, the insertion of the abutments etc. was all what I came to expect from the reliable Bicon system.
But despite my following all standard procedures, the 2 STEALTH shouldered abutments have come loose about 15 times by now. Both have been faced with Ceramage Composite directly by a dental technician.
2 months ago, I replaced the crowns. Additionally, as the forces acting on #13 + 14 are presumably fairly strong, I have ground down the contacts to a completely passive status (which I normally do not do).
Since then, #13 seems stayed in place up to now.
But #14 keeps falling out after twisting (see photo). There is no more approximal contact to 13 and 15, also occlusion is perfect.
Bicon has not been able to give me relevant advice on the issue so far.
We have internally discussed the possibility of joining the two abutments like we sometimes do with other implant systems but as this seems to be an experimental procedure with the Bicon system we have not yet decided on that one.
I would appreciate if you could help me resolve the issue. Does anyone have similar experiences – and solutions maybe?
![]Bicon Implants after inserting new abutments and crowns #13+14](https://osseonews.nyc3.cdn.digitaloceanspaces.com/wp-content/uploads/2014/02/001-Bicon-Implants-after-inserting-new-abutments-and-crowns-13+14-e1393176748481.jpg)Bicon Implants after inserting new abutments and crowns #13+14
![]Bicon Implants with new abutments and crowns, #14 twisted, shortly before falling out](https://osseonews.nyc3.cdn.digitaloceanspaces.com/wp-content/uploads/2014/02/002-Bicon-Implants-with-new-abutments-and-crowns-14-twisted-shortly-before-falling-out.jpg)Bicon Implants with new abutments and crowns, #14 twisted, shortly before falling out
![]Bicon Implants with new abutments and crowns, #14 twisted, shortly before falling out](https://osseonews.nyc3.cdn.digitaloceanspaces.com/wp-content/uploads/2014/02/003-Bicon-Implants-with-new-abutments-and-crowns-14-twisted-shortly-before-falling-out.jpg)Bicon Implants with new abutments and crowns, #14 twisted, shortly before falling out
![]Bicon Implant, crown + abutment #14 after falling out](https://osseonews.nyc3.cdn.digitaloceanspaces.com/wp-content/uploads/2014/02/004-Bicon-Implant-crown-+-abutment-14-after-falling-out.jpg)Bicon Implant, crown + abutment #14 after falling out
38 Comments on Bicon Abutments Keep Popping Out: What Can I Do?
New comments are currently closed for this post.
DR M Buz
2/24/2014
It looks more occlusion issue than others, is the case canine guidance or group function at the right side. are you sure that there is no premature contact in the lateral excursion in the premolar crown, Does the patient has any parafunctional habits. it looks like that starting from the lateral all the right side was restored with fixed prostheses??can you tell the cause of the teeth loss and restoring at this side
User J
2/24/2014
This is likely related to occlusal forces twisting the crowns out of place when the patient bruxes or moves in lateral excursive movements. Often times if the abutments come loose after more than two weeks in function the culprit is an un-balanced occlusion. Bicon crowns need to be tapped into place to engage the abutment connection. Was a seating jig used to tap these crowns back into place? Did the Bicon lab make these crowns? If you send the crowns to the Bicon Lab they will make you a seating jig to ensure you are tapping along the abutment post axis. In the close-up photo of the crown and abutment it looks like the post may have been modified or polished which will prevent the locking taper from engaging properly and could cause loosening.
CRS
2/24/2014
I would suggest mounting this case and diagnosing the occlusal issues, the wear facets on the lower teeth are visible on the photos. I don't know this system but is it possible to restore the implants with provisionals while determining the occlusal issues? A bite guard may be needed long term. How are the implants holding up radiographically? With 15 loosenings you may want to have a prosthodontist give you a hand here this is tough to do piecemeal in the mouth and obviously what has been tried so far is not working. good luck, but it is most likely occlusion and/or parafunctional habits. How were the teeth lost originally?
Dr. Best
2/25/2014
I would suggest to talk to the Bicon experts directly, Vin, Mauro or VJ might have a simple solution.
Rand Ollerton
2/25/2014
Once you have followed the other suggestions I would recommend that you make certain that bone architecture is not stopping the abutments from completely seating. The Morse taper creates a cold weld. After tapping to place with 6 bangs, it should be impossible to get loose without forceps.
Dr J
2/25/2014
Switch Systems! You are not the only one that has this problem with Bicon. It's not good a practice builder.
DrKR
2/25/2014
I have fought with this same problem, it usually occurs at either canine and occasionally the first premolar. I have tried remaking and adjusting the occlusion with very little success. The only thing that I have found that works is to create an internal lock with the adjacent implant crown (don't just bond them together, the bond will break) It does require flossing under the now two unit bridge, but it stops the micro rotational forces that break the friction weld.
SET
2/25/2014
Here's a longshot.... I once had a somewhat similar situation, placed a nobel biocare on #22 (upper left lateral), patient with massive O.J at more than 10 mm, no occlusion whatsoever on crown and it kept coming off. Fixture picture perfect (by NO means are all my fixtures are pic perf). Replaced abutment with gold custom, still kept coming off every 2-3 months. After 7-8 de-cements, pt admitted "I use this tooth to cut sowing threads, it's my strongest tooth". Have u asked the pt if they chew pens, open bottles, or parafunction in a way they don't consider abnormal? Despite this, it is almost certain it is an occlusal issue, as aforementioned take xray & check bone levels. Good luck
John L Manuel, DDS
2/25/2014
Minding a few basic principles can prevent this problem:
Do you have an x-ray showing the side view of these in place? Are they fully seated without any fibers, bone, etc., in the way? A very careful, cleaning and seating protocol is needed as well as x-ray confirmation of full seating on any abutment. Did you clean w/ alcohol and the correct sized cotton tip?
The long Buccal cusp overlap would seem to invite bruxing. Most implant systems cannot handle Buccal/ Lingual interferences to centric. Occlusion needs to be along long axis, with no interfering approaching ridges, cusps, etc..
What size post? 2.5 mm is best for bicuspids. It was designed to control unwanted rotation and loosening.
For certain, the tapered surface is ruined. Once it is marred there is no cold weld.
Re Interproximal contacts: I use broad flat contacts, fairly firm... 2.5 x 3 or 3 x 4 in molars.
Please post x-ray of seat.
In summary - this is a fixable problem with care in cleaning the implant well (keeping it clear of fiber, bone, etc), flat broad firm contacts and clear entry to centric occlusion.
I've used Bicon for years and this has only happened early on, when the well was not cleaned of fiber, etc., for us. You may need to use a drill to clear out bone if the tool for this does not work. Bicon's frequently have bone growing over the implant top which can prevent full seating.
John L Manuel, DDS
2/25/2014
Great comments, SET and DrKr. Even a slightly "wrapped contact" can help where the bi meets the Distal of the cuspid.
As for bridges... Yes, Bicon's work better alone, but the 3.0 mm ones need bridging at times. I had a lady needing a bi (12) and molar (14) who'd had a periodontist graft the sinus... but not enough bone for 13, so we ended up putting in a 3 unit bridge and it's held well for about 6 years now.
If the patient is at the "end of her rope" on this, You could just put in two new abutments and a temprorary (well done) acrylic bridge which could provide some flexibility in load transfer. It would not be the end of the world to have a Zirconium two unit bridge cemented with compomer. Make certain the implant wells are as clean as possible. Hopefully they don't show the scarring of the abutment post.
John L Manuel, DDS
2/25/2014
Also, a more vertical implant position is recommended at the outset since a high Palatal slant makes for a strong rotational loading, i.e. the Buccal flare of the implant means it's being loaded heavily from the side vector, causing rotation.
Any engagement to resist rotational loading would help.
G. Scott Hanosh DDS
2/25/2014
I have had similar problems with some anterior bicons.
Have been round and round with Bicon experts about excess bone preventing seating,
eccentric interferences. Nothing helped.
I still use bicons, but am more cautious about location and patients occlusion.
I use screw retained systems as well.
Contact me for additional comment if you'd like.
Andy K
2/26/2014
It's better to use 2.5 mm post for maximum retention in restoring single crown in the upper anterior region (canine to canine) with Bicon system.
In this situation, since Ceramage Composite is used, it's better to grind distal of 13 (without taking it out, since it has been stable ) and mesial of 14, then give good 3/4 taps on 14 and bond them together with some good amount of composite. Otherwise new splinted crowns will be the next option.
Charles Schlesinger
2/26/2014
if the crowns/abutments have come out 15 x's- the morse taper connection is no good anymore. The wear that is evident on the taper will not allow the taper to do its job, which is hold by friction afforded by the resistance form of the taper.
Did you change the abutment along with the new crowns, or did you lab just try and re-use your abutment after removing the crown?
John L Manuel, DDS
2/26/2014
As CRS said at the outset, there is an occlusal balance problem here. I see signs of Anterior and Buccal interferences and closed vertical. A restrained lower jaw will try to grind and force it's way through any amount of chrome/titanium, etc.. It's like riding a horse with a bur under the saddle... no amount of cajoling, rein yanking, or cinch tightening will help until you remove the bur... i.e., the grinding stimulus in this case.
Also, without x-rays it's hard to tell, but sometimes a divergence between the implant/abutment entry angle and the interproximal crown angle can interfere or prevent full seating. I have my crowns made separately from the abutment and ensure a clean, full abutment/implant fit prior to cementing the crown. In most cases, I can then cement the crown on the model and then seat both as one unit, but if the implant angle is even a little off the insertion angle, you won't be able to fully seat the abutment.
Great advice so far from all corners!
Dr. Nitin Sharma
2/28/2014
The culprit is only 44( lower first premolar) creating unexpected torque at distal to 13 and mesial to 14. Take an mandible occlusion clinical of pic and pls share
Richard Hughes, DDS, FAAI
2/28/2014
Remake the crown so that the occlusal stop is on the lingual cusp, without ANY ex cursive contacts on the lingual incline of the buccal cusp. Yes, it is intuitively obvious tho the casual observer that there is an occlusal interference issue. This usually happens to a maxillary anterior single crown when using the BICON (anterior looping).
If you like the Bicon system, and I do, then consider the Quantum Implant System, Plantation Flordia, USA.
Raul Mena
3/1/2014
There are a few reasons that may cause this problem. In order to properly diagnose the cause you need to post an XRay and also you need to mention if it is a straight or an angled abutment.
Lessening of the abutment may be caused by:
Bone or soft tissue preventing the abutment to be fully seated
Angle abutment with occlusal interference of some pathologic habitual movement
The lab may had damage the taper post.
The implant or the abutment could be out of manufacturing tolerance.
If the implants are divergent you can place two abutments, take an impression and do two splinted porcelain metal crowns and cement them.
It is not normal to see these problem on posterior crowns
Bicon is a good system, I placed many of them for years and never had that problem with the exception of 2 or 3 upper anterior cases.
For full disclosure I am the president of Quantum Implants.
ut
3/2/2014
Thank ye all for the extremely helpful comments and hints! Here´s additional information and my replies to your questions & suggestions:
- #16 (part of the bridge) was extracted about 30 yrs ago (pt is 62 now), reason unknown. I renewed the bridge #17-15 last yr before the implants.
- Yes, I have followed all suggested standard procedures which in my practice include a custom made seating jig and the meticulous cleaning of the well and removal of all obstructions (including bone before the first seating).
- I have used a 3 mm abutment (STEALTH); at present we are working on the second replacement as the first two abutments were from the same lot.
- I had already talked with Mauro in Rome, and he told me about similar cases where Bicons implants (incisors) came loose/rotated. He suggests fitting again and again until it finally stays in place (like #15 now seems to do, please knock on wood, my friends) OR – as a "final" solution a bridge like several of you suggested, too.
- John (L. Manuel) thanks a lot for the suggestion of separating crown and abutment fitting etc. I might try to do it that way.
- Two X-rays attached as well as a close up of the implant well plus 2 photos of the lower premolar region (so you check on wear/occlusion issues).
Richard Hughes, DDS, FAAI
3/3/2014
Dr Mena,
Thank you for that excellent explanation.
Your implant system is very well designed and has a lot of flexibility both surgically and prosthetically. Go Quantum Implant !
Raul Mena
3/3/2014
D. Hughes,
Thanks for your kind words, coming from you it means a lot.
Raul
M.Mohamed
3/4/2014
I have been using Bicon in the posterior and the lower anterior regions only .I avoid the upper anterior site . This is because of its lack of anti rotational features and a fixed torque measurements. You can easily place and remove the abutment/crown from the implant well but by how much torque or force? No body knows.
When I attended their class in 2010 the lecturer admitted that they had a problem with 2mm well implants when they are placed in the upper anterior area. To the extent in one case they were forced to remove the implant after several times of abutment /crown loosening.That is why they introduced 2.5 the max implant, and even with this they claim that it is more strong and resistant to loosening by 75%.
It is a good system yes but in a situation like the anterior area I will be cautious.
I don't want to make my patients suffer. After 15 times you will lose the patient's trust
Good luck and thank you for sharing
POA
3/4/2014
I have experienced this with about four cases of anteriors - most 2mm wells and 1 3mm. Generally does not happen with 2.5s and 3s. As advised, check for crestal bone interference; don't sacrifice contacts, as there is a risk of food impaction and developing localized perio => implantitis; splinted two anteriors in one case which worked well and there has been long-term stability; a friend successfully used sprinkling gold dust bought from a jeweler into the well to improve the friction. Lastly, check for canine guidance which should eliminate excursive contacts in working and balancing function.
David Vaysleyb
3/21/2014
Switch to a screw-retained abutment or solid abutment. The torquing mechanism reduces "fall-outs". Splinting helps too.
raul mena
3/21/2014
If you switch to a screw retained then you will not be even able to obtain the benefits of a locking taper system .
For anterior cases I use Quantum taperlock with a thread at the end of the locking taper post. That prevents lossening of the abutment.
Qantum ofers 3 different implanto abutment connections on the same implant body. For the purpose of true disclosure I am the president of Quantum implants.
I am not being critical of bicon, since I also believe that bicon is also a good implant system.
Raul Mena
Anton Andrews
4/6/2014
Your patient has severe TMD. Start with the NG to neutralize extreme grinding forces . Does not matter how much you adjust the bite, it will only give you some time until lower teeth will erupt and will knock off your crowns again.
Cases like yours is the reason why I do not use bicon implants .
Question to Dr. Mena - can you splint Quantum implants?
Raul Mena
4/6/2014
Anton,
Yes you can splint Quantum Implants.
And again Quantum has 3 types of connections in the same implant body.
A) TapeLock, B)TaperLock with a thread at the end of the taper post, and C) Bevel Hex.
It is a unique system because implants can be placed anywhere from 2 mm below the crest to 2mm above the crest.
The same implant can be placed with a Thread-In or a Push-In Technic,
The Osteocompressive thread is ideal for Immediate Loading, Immediate Placement, Immediate Fixation.
There are many other features unique to Quantum
Raul
Anton Andrews
4/6/2014
Raul,
what about CAD/CAM compatibility?
Raul Mena
4/6/2014
Anton,
Yes we have Cad Cam compatibility
Raul
Dr ali AlKaissi
9/26/2014
Dear Dr
I'm a bicon user, I advise you to avoid integrated crow abutment
And try to tap abutment adequately then you can cement the
Crown and avoid any contact in all directions
Richard Hughes, DDS, FAAI
9/27/2014
Single bicon implant abutments can and do become dislodged due to the off axial loading ( remember the envelope of motion). I do not recommend using BICON implants to restore anterior regions in the maxilla or mandible. The Bicon is great in the posterior.
Better yet switch to using Quantum implants. One can screw or tap in the implant and the abutments can screw or tap in. Quantum implants also have much more prosthetic options.
If you do convert to Quantum, take the time to learn the system. It's very well thought out surgically and prosthetically. I switched and I see the benefits. I'm not saying that BICON is a bad system but you will reap the benefits of a greater BIC with a shorter implant and have sound prosthetics.
John Manuel, DDS
9/27/2014
Bicon implants, abutments and. Downs benefit greatly from having the implant axis, the abutment insertion axis, axis and the crown insertion axis close to parallel. In addition, one can reduce food imp action under the contact and load sharing. Y having broad, parallel contact areas. I shot for 2mm vertical and 2-3.5 mm horizontal contacting areas. These broad contacts require less pressure to achieve resistance to food intrusion.
One must evaluate adjacent teeth and Polish or prep them to allow this close to parallel of all three implant components.
This also greatly reduces off axis loading and abutment loosening.
So, at the planning stage, one should reduce angulation, or compensate.
Until recently, precise custom guides, and/or close operator precision were required. There is an excellent "MD Pilot Drill Guide Set" made by Wamkey.com which simplifies achievement of parallelism. First, the operator plans the desired implant axis and insertion paths. Secondly the adjacent contacts are shaped to match this target path. Thirdly, the operator chooses an MD Pilot Drill of the width matching the final crown width, or the desired distance away from a neighboring tooth.
These guide drills have a cylinder atop each bit, the width of which is to match the final crown width, so holding the "fat" cylinder against and parallel to the adjacent tooth automatically achieves the three desired parallel axes which reduce or eliminate off axis loading.
While they're handy for most implant systems, theyre a boon to the Bicon system in that loosening forces are almost eliminated.
amgdd
9/28/2014
"Thirdly, the operator chooses an MD Pilot Drill of the width matching the final crown width"
A pilot drill is supposed to be a "pilot" drill.... thus allowing corrections to "axial angulations" prior to final sizing... is it?
Not, never matching the MD width of crown.
How does the "almost always narrower" B or F- Lingual width is accepting this "concept of selecting drill" and solving the "angulation problem"?
John Manuel, DDS
9/29/2014
While I apologize for quickly posting the above on a tiny screen w/o editing features, I stand by the position that these devices can be of significant help in aligning implant bodies, abutments, and crowns, to the neighboring structures. I have no financial stake in these products, just think they are a handy adjunct to the process.
1) Pinpointing the proper guide drill entry spot is simplified by the operator's placing the wide cylinder against the adjacent structure, thus automatically placing it that selected distance away. Of course it will not magically center the guide pin Buccal-Lingually over the targeted bone site.
2) Parallax and perspective distortions can make it difficult to visualize what the final effect will be of drilling a pilot hole with visual guidance alone. There is a great advantage in being able to visualize the position of the final crown, etc., as it relates to the ridge, the fixture, the bone, the tissue, the occlusal plane while one is in the initial stages of placement.
3) The guide drill length of these is only 6 mm or so. One still must use a longer, normal guide drill. One has many opportunities to alter the entry and path with subsequent drills and reamers. This is just a simple way to get a good start with a good feel for what the final result will be.
The large cylinder helps one to line up with important structures.
John Manuel, DDS
9/29/2014
If your concern over the B-L dimension being smaller than the M-D dimension is a fear of interfering structures, the tongue and cheek are freely movable and usually retracted. Impossible for them to move the position against the operator's guidance.
If your concern over the B-L dimension being smaller than the M-D dimension is worry over damaging the cheek and tongue, note that the cylinder is smooth and shiny and that those structures are normally retracted during the guide drill application.
SANGLYONG YOON
2/15/2017
1.Check the contact. If too tigh,t make it loose.
2.Remove the prosthesis and check the retention of abutment alone.
3.Abutment alone shows good retention, then make a new prosthesis. If not, try another abut. And all above does not work then,
4. Make the post 0.3-0.5mm long. In other words, cut down just the starting point of hemisphere. This could remove the interference of not complete seating. Bicon’s milling accuracy is not accountable. Sometimes the post is too small or sometimes the well is too big. Visit IDS 2017 and find out LOTA Implant Company at Korean Booth
John Manuel, DDS
2/16/2017
Since the starting point of the hemisphere is 2mm above the implant, interference in that area is unlikely. Basically, make certain the tissue/bone around the implant is cleared away. I often use an extended length football diamond to do this since the Bicon tissue trimmer just kind of shreds the surrounding tissue. Most common loosening is from tissue tags, incomplete seating, and/or lateral rotating forces.
Try fairly snug, broad, flat contacts to reduce rotational forces. Best prevention is implant body alignment.
Dr Robert Cadalso
7/18/2017
I had a similar experience and found that the tissue was the culprit., Make you you make a releasing incision prior to seating the crown? I know it sound s simplistic but double check that pressure from the tissue being compressed is not what is eventually allowing displacement of the crowns.
Bicon){kind=link}
Bicon){kind=link}
Bicon){kind=link}
Bicon){kind=link}