Changing the Direction of an Implant: Proper Protocol?

Dr. P. asks:
When you get to the stage where you have already placed your osteotomy channel and you are down the implant fixture and you take a radiograph and see that the fixture is malpositioned or misangled, what should you do? Is it possible to change the angulation or position of the fixture at this stage simply by using the torque wrench? How do you manage this problem? Is it necessary to unscrew the fixture and to redrill the osteotomy?

20 Comments on Changing the Direction of an Implant: Proper Protocol?

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Perio
6/12/2011
You shouldn't have this problem if you take radiographs with direction indicators as you drill your osteotomy. At that point it is easy to change angulation using a Lindenman side cutting bur. Once the implant is seated it gets challenging because you run into the risk of losing primary stability. You can usually make minor adjustments while you are seating your implant. But if you are way off I would remove the implant and graft and redo later. You do not want to run into the same problem as one of our colleagues who posted a case recently on this site.
dr.med.-dr dent Alessandr
6/12/2011
first drill, than yoy take a guttaperca point and put in the hole,than a good rx to estimate the appropriated deep and the correct position. if not, you can temptate anyway another drill hole. never insert a fixture before this evaluetion.
DrSenGupta
6/13/2011
Agreed to above ...but Gutta Percha ? Why ? how about a guide pin or the drill bit itself?
John Manuel DDS
6/13/2011
Most implant systems use pilot drills initially, for which the first few sizes have alignment posts for clinical and x-ray evaluation at the onset of the prep. Some systems allow correction in the next few reamer sizes. If your implants are of the type which does not require intimate bone contact , you have a whole series of opportunities to change alignment. The Bicon system, especially the shorter versions allow you to prep from one direction and then pivot the implant into desired alignment, even at the end of bone prep and after insertion. The 5x5 and 6x5.7, etc. Are almost "ball shaped" and allow great range of adjustment after final insertion.
Mark P. Miller, DDS, MAGD
6/14/2011
Wow. Respectfully, these issues should have been behind us decades ago. Ever heard the expression 'measure twice, cut once."? If you absolutely had to have a cabinet 24-1/2" wide and it came in at 25" wide, would you accept it? Of course not. We have taken intra-operatives digital x-rays of implant placements in our office for years. Prudence and professionalism says that first you drill the initial pilot hole where you want the restorative platform to be. Drill 3-5 mm further and then, like others have posted, place an alignment pin and take an x-ray. All the companies have alignment pins and it makes no difference which one you use. Drill a 2.8mm hole? Use a 2.8mm alignment pin and see where you are. Angle off? Keep your restorative platform hole at the right spot and lean into the drill to reposition the angle. This can be done several times during the procedure. There is no excuse to finalize an osteotomy and be off. Every industry has checks and balances, quality controls, and exit strategies. Dentistry should not work in a vacuum. An open margin on a crown of 1.0mm is not tolerated. Why should an off-angle osteotomy be tolerated? There's really no excuse if attention to detail is followed. An earlier post was exactly correct. If a practitioner has missed the mark to this extent, graft it, learn from your mistake, and don't do it again. 'Trifles make perfection, and perfection is no trifle.'
Carlos Boudet, DDS
6/14/2011
Dr.P: Always take a periapical film with an alignment indicator in place very early (at pilot drill) to verify proper angulation, depth, etc... This will allow you to correct any misalignment before the final osteotomy. To answer your question: If the fixture has been placed and it is malpositioned or misangled, you have to make a determination whether 1- you are willing (or able) to restore the fixture in such a position without it being detrimental to the patient or 2- You are going to remove it and place it the correct position. This may require reinserting at a different angle, or aborting, grafting and delaying the placement. Most of the time a malpositioned implant will create complications for the patient such as unnecessary bone loss, difficult access for cleaning, etc... When a malpositioned implant does not cause a problem for the patient, sometimes it causes a problem for the restorative phase, requiring a more expensive and time consuming restoration. Thanks for sharing your question with us and good luck!
Steven
6/14/2011
Using a Lindenmann bur is a possibility, but unless you are going to increase the diameter of your implant, you will probably find that your new osteotomy hole is too large and your implant will have minimal stability.
John Manuel DDS
6/14/2011
I just want to clarify, that the ability to change an implant's abutment angle AFTER placement is a great advantage, not a "mistake". Yes, it is a mistake not to have had a plan and measured steps along the way as some have advised. But, some sites have better bone in an undercut area which the operator can easily reach at an angle and then upright the implant, and have a three walled defect to bone graft from the side. So, PLANNING to use a system which allows the operator to tweak the abutment shaft angle after placement can be a valuable adjunct to everyday surgery also. John
Sean Meitner DDS
6/14/2011
First of all it is very to avoid this problem by starting with a making a surgical guide in your office using a radio-opaque guide sleeve . You can take an X-ray and evaluate the mesio-distal angulation with a periapical x-ray or you can evaluate both the mesio-distal and bucco-lingual planes with a cone beam X-ray. then you can evaluate the angle with a protractgor and correct it if it is made with a bendable guide post before drilling the osteotomy. Once the implant is placed if is very difficult if not impossible to change the angle with out going to a larger diameter implant. There are several ways to make guides, most recquire an impression and a curing light and light cured acrylic and a guide sleeve of an appropriate diameter cylindrical or open faced and a guide post to place the guide sleeve on. The patient is charged for a template. If you explain to the patient what and why you are doing they do not complain and actually appreciate it. The insurance code is 6190 "surgical implant index"
Sean Meitner DDS
6/14/2011
Look on the internet to find surgical guide components for fabrication of a surgical guide
ERIC DEBBANE.DDS
6/14/2011
agree withh most of the above concerning the proper use of guide posts first . The only system that I know of that can be easily realigned even after insertion would be Nobel Active . Otherwise you will need to regraft and go back after removing the implant . Unless you can go to a wider implant and drill into very fresh bone to regain alignment .
David Mashburn
6/14/2011
Even the best planning and surgical guide use can result in an implant at an unintended angle. If the malpositoned implant has good primary stability you should remove it, graft and wait a couple of months and place it again. The Bicon System has hand reamers that cut on only one side and be used to correct implant position. Since the Bicon implants have a passive fit, you can add graft material to the corrected osteotomy and work in the implant by hand. This is one of several systems we use in our office as we have found that no one system is perfect for every situation.
Richard Hughes, DDS, FAAI
6/14/2011
One can use the Lindenmann Bur, this is an excellent way to correct the osteotomy or other burs. Then graft with a particulate graft material and place the implant in the proper location and with proper angulation. Confirm with mouth mirror, trial abutment and periapical. Do not immediate load this implant. These thing do happen. What one does about it is the issue.
Abg
6/14/2011
osteotomy changes with pilot drill possible, initially. But once the entire osteotomy procedure is done with and you get to know that the fixture is misaligned. after implant placement you cannot help but remove the fixture graft the site and wait.Planning initially before drilling is very important. This is where radiographs,CTs, surgical guide templates come into picture.
benny
6/15/2011
Direction of implant can be changed during incertion of implant in all planes i.e.buccal,palatal,mesial & distal.But after fully seating implant if we want to make changes then our implant goinf to loose its initial stability,which is of utmost important especially in maxilla.Best solution is to confirm implant osteotomy by taking x-rays with parallel pins or drills.
josh keren
6/16/2011
dear friend when you ask for advice please give maxumum information available. regarding your Q.assuming that the malposition is on a M-D direction Iwould consider an implant who has multiunit abutment which will allow you to correct the angle eg: nobel biocare Implant as 17and 30 degrees Abt. BTW tilted implats are not sciencfiction anymore. after positioning the implant you should consider C.T. (perforation) GOOD LUCK .
PM oral surg
6/16/2011
I agree with intraop xrays. I take one after the pilot drill and sometimes of other drills if I realign. Always take one. You'll be suprised how often you're off just a bit, mesiodistally. Implant align is a company that helps you do this. I found them on YouTube.
Blah
6/16/2011
Agree with the pilot drill being the key. I like how people think taking CT will help them align the implant better. Unless the CT is attached to a robot and the robot is doing the drilling, I still can't understand how the CT can help me stop my hands from shaking and place the implant 'exactly' as I planned. I have yet to see anyone place their implant EXACTLY where they intended to go accurately and consistently. Same thing with the surgical guide, have yet to see anyone with 100% accurate placement.
Dr. Samir Nayyar
6/20/2011
Hello if u're already done with the procedure then just relax. But in future after drilling half the desired length of the pilot drill, take a rodiograph and again after drilling full length.
Baker vinci
7/10/2011
Blah, your information is useless. It's Just about time to retire for you. You don't believe in research, cbct, surgical guides and using antibiotics in the face of a purrulent INFECTION. I meet guys such as your self all the time , who suggest because something has worked in the past, why change. It was just three decades ago when dentist were using the same needles on different patients , and wet handed dentistry was the norm. Do us all a favor and stick to scaling and root planing, or do you not believe in that either . Your perio colleqes that do know what they are doing must be cringing at some your thoughts. Bv

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