Incompletely Seated Implants: What Should I Do?

Dr. CP, a general dentist asks:
I am a beginner in implant dentistry and today I put my first implants in sites # 29 and 30 [mandibular right second premolar and first molar; 45, 46. When I attempted to torque the implants down to their final working length, neither implant went all the way. The implant platforms project a few millimeters above the bone level. These implants are designed to be installed to the bone level. I was not sure if I should untorque and remove them and drill wider and deeper osteotomies. I left them in place. What should I do next?

8 Comments on Incompletely Seated Implants: What Should I Do?

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Carlos Boudet, DDS
5/23/2010
Dr CP You left out a lot of details that could be helpful in giving you suggestions, such as the design or brand of the implant, whether it is straight or tapered, the size of the polished or machined collar, diameter, etc... It is safe to assume that you did not drill your osteotomy properly, and the implants needed to be removed, the osteotomy redrilled and/or tapped, and the implants seated flush with the bone level if that is what they were designed for. My suggestion is that you evaluate your implants radiographically at a week's post-op and determine how far above the bone they were actually placed. If the platform is 3mm above the bone and the tissue is 3mm thick, you will not have any soft tissue for an emergence profile and the patient will not have an esthetic result. If you explain this to the patient and they accept this, you should be able to restore them. If however, you or your patient want an esthetic result and not a compromise, you will have to remove them and place them at bone level. Good luck.
sb oral surgeon
5/24/2010
I have sen alot of beginners having this problem. I think in your case it stems from a variety of factors: 1. You were probably in dense mandibular bone. The drilling protocols are very unforgiving in this type of bone with certain kinds of implants. If you are using tapered implants, your problem could be improper osteotomy shape and depth. In dense mandibular bone I prefer parallel walled implants and tapping my preparartions. Implant companies sell their implants on "self cutting threads" and excellent primary stability. You instinct will be to under-drill so you assure good primary stability. again with taperred implants this probelm is even worse. 2. Your first implant cases, especially in the mandible where there are nerves and undercuts to avoid, are stressfull. Your instinct will be to under-drill your depth to remain a "safe" distance from the nerve. You need to know the anatomy and trust your hands. Scans can be helpfull here so you can truly know what you are drilling into. When your platforms are above bone level, you most likely have implant surface above as well. Depending on tissue thickness this could become a peri-implantitis nightmare very quickly. Treated implant surfaces that become contaminated with plaque are very complicated and frustrating to deal with. The prosthetics on your case may be an issue here. If you planned your case with a bone level implant and you are now above, do you have enough occlusal clearance from the opposing arch for an abutment/crown? You need to be able to answer these questions. If you cannot you have no business doing implant surgery. Remember to put yourself in the chair. What would you want in this case if you were the patient?? You would want the case done correctly with the best chance for a stable long term outcome. If you can't provide that, take your medicine, take the implants out and refer.
Richard Hughes, DDS, FAAI
5/25/2010
To sb oral surgeon, I have seen this with experienced docs. You brought up evcellent points as per the anatomy and density and implant design. Sometimes placing the implant short can be intentional. One does not always get a perio condition from this, if mannaged correctly. The same goes for the prostho as well.
eric-sb oms
5/25/2010
dr hughes- regarding the prognosis of supra-boney implant surface: most surfaces these days are very rough (ti-unite or nano-tite to name two). while some gingival biotypes can handle this, my over-all experience has been negative. once this stuff gets contaminated with plaque it becomes a chronic source of inflammation and almost always leads to peri-implantitis type lesions. i would not want supra-crestal implant surface in my mouth. in the olden days implants had polished collars of 1-2mm. this was a great idea and i see excellent maintanece of these fixtures. by the way, i always enjoy your comments.
Gregori M. Kurtzman, DDS
5/25/2010
As you indicated best to unscrew the implants, drill the sites deeper (if anatomy allows) and reinsert. Keeping the fixtures that high will create restorative issues if the fixture is designed for bone level placement.
Daniel Kim
5/27/2010
Assuming the correct length has been prepared, you have to be flexible in the sequence given by implant manufacturers. The final drill width varies depending on the bone density. Denser bone requires a wider final drill and vice versa (for softer bone). If the site is too narrow the implant fixture will get stuck in denser bone (I know because i have experienced it often). Simply back the fixture out and prepare a slightly wider site before reinserting.
mohammed Jasim
7/19/2010
tapping is very important in dense bone, full length tapping
samantha nigatsi
10/29/2010
the ammount of bone remaining around implant after isertion is an issue too.if its too wide one can loose bone around neck and reveal implant hight u dont intent to.

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