I placed a straumann 8mm BLT 4.8 approximately 1mm subcrestal with a cover screw.
At the time of placement, I used my axial indicator to make sure the osteotomy had a floor and not a drop into the sinus I felt I was tapping/hitting solid bone but possibly one aspect of the osteotomy has a perforation due to the sloped sinus floor - I’m not sure but based on my planning this is an assumption. I had been informed by senior colleagues in the past a small sinus breach is not ideal but plenty of studies show 1-2mm within the sinus and no issues ?
I profiled the crest which in retrospect I wish I hadn’t I did this because it felt like D1/D2 bone although working on the posterior maxilla.
When torquing my implant it pretty much hand torqued and when it reached the osteotomy bottom it span but I didn’t want to put any more pressure in case of completely pushing through the sinus. This surely indicates low primary stability.
I took an X-ray to assess implant positions and when I came to double check tighten the cover screw the implant didn’t budge more stable without spinning
I decided to leave the implant in and draped the implant and it’s osteotomy site with Bio-gide (since I was using it elsewhere) over the crest and primary closure was achieved.
I was prescribed antibiotics and advised patient any sinus symptoms to let me know.
I’m stuck now I’ve been reading contradictory information if the primary stability low the implant is sure to fail and if it has breached the sinus massive complications etc urgent and I should go back in and remove it immediately. Others say monitor for sinus symptoms and since its buried and subcrestal monitor, primary closure see if OI occurs. I’m lost as what to do, any advice would be much appreciated.
Like “davidimplants” I have also placed plenty of fixtures 1-3mm into the sinus with no complications and primary stability, IMHO, is the most overrated indicator of future success ever. I always try to avoid a sinus perforation and decent primary stability is nice to but a fixture placed through the floor with low primary stability is not doomed for failure.
On another note since you already place Straumann if you use a tissue level instead of the BL then you aren’t obligated to place the fixture subcrestal, (Zero Bone Loss Concept) which would prevent it from needing to be placed into the sinus. The flared collar on the TL also provides some resistance against possible intrusion into the cavity. Some of the early ITI studies actually advocated for TL implants when placing immediately into a grafted sinus for this purpose…
Yes I think in future I will place TL when working in the sinus. In this case The axial indicator appeared to be bottoming out hitting bone but that doesnt mean I didn’t perforate at a lateral aspect. I am now concerned about migration into the sinus ? Anything I should look out for. Patient emailed currently has swelling and no pain but I expected this due to cortical nature of the bone
On a separate note for a BLT implant how much beyond the osteotomy created is it easy to torque, is it a bottomless pit ?
If I understand your question correctly I think a BLT, due to the degree of taper, should maintain a high torque well beyond the osteotomy into a cavity. While it doesn’t happen often, to the best of my knowledge I have never experienced it, I was instilled with a healthy degree of fear early on regarding a fixture being displaced into the sinus. For this reason I have always used a TL with a flared transmucossal collar or placed a flared healing abutment on a bone level fixture at the time of placement when placing immediately into a manipulated sinus.
Ok scotty in future TL for sure. Disregarding this case what I want to understand and always am apprehensive how far can one torque beyond their prepared osteotomy assuming there is cortex bone at the base. With BLT self ‘tapping threads’ I imagine you still can’t torque the implant very far beyond the drilled osteotomy ?
I would assume that those fixtures with self tapping and/or aggressive threads should behave just like a drywall screw and thus be free to insert well beyond the prepared pilot hole. Take a look at the protocol for placing the Zest Locator implant which similar to the old MDI is placed into a small pilot hole drilled 2-3mm short of the final fixture length so in this case the protocol is dependent on stability beyond the osteotomy…
the key point is RISKS. RISKS don’t necessary become complications. Often, there’s 8-10mm of sinus floor and after a sinus bump. there’s barely enough for 10-11.5mm implant. your sinus is sterile your implant is sterile. the risk of sinus infection from sinus exposure and perforation is very low. I’ve only experienced sinus infection 2 times after implants placed in 1st molar position in conjuction w/ vertical sinus lift. Oddly, i never experienced a lateral sinus lift infection. After removing failed implant, treating sinus infection w/ PO antibiotics. and allowing sinus to heal for 6 months. the 2nd time i place implant and sinus lift. healing was normal. So i doubt it’s an implant problem. rarely the wrong bacteria slip into sinus and cause infection, that’s all. So dont be too hard on urself james1989. if infection does happen just deal with it. not end of world. u get to try again. And mostly i find more success w/ under torqued implants during placement than over torqued. just bury the implant and wait. i assure you after 4-6 months of healing the implant will be like a rock.
Amen!!! For the life of me I will never understand the obsession with primary insertion torque when the most successful fixtures of all time are parallel with non-engaging threads designed to be routinely inserted at relatively low insertion torque.