[Diagnostic / Planning]  how long do you wait before calling it a failure?

Hi everyone,


I would appreciate your input on this case.


Was placing upper premolar implant for a referring dentist.


The dentist had extracted the tooth and placed a socket preservation graft with allograft bone  4 months ago.


Went in and found that the graft had not taken and buccal bone was totally gone. The only CT scan I had was pre-extraction.

Should have aborted mission but patient wanted me to try anyway so regretfully I placed the RP 13mm implant and it torqued in to 35ncm.  But 1/4 of the implant's buccal threads were showing so I grafted with puros bone and placed a palatal CT graft over it and buried it.  I used a bone trap but there wasn't much collected.


I got primary closure and told the pt that unless the bone grew in around the implant it would probably have to come out and we send her for a block graft.



Can this work or is it doomed for failure?

If I leave it for 8months and then Ct scan it am I wasting the pt's time?

I plan to flap it and go and see what is happening but when?

How long would you wait?  If it's not going to work I want to get the implant out before it's too hard.

Has anyone done anything like this with any success?






by Cindy Sidhu at Thu, May 19, 2011 3:20 PM

1929 Views | 3 Replies


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Mark Kwon Replied at Thu, May 26, 2011 5:05 AM

Hi, CL. Very good post. key questions to ask for any compromised cases : 1. How was the remaining host bone quality? Remember, sometimes, quality of bone is more important than quantity. 2. Am I able to achieve primary stability > torque; when grafting around buccal area of exposed implant, the implant must be stable; 3. Am I able to place the implant palatally? - very important!! In order to achieve bone growth, you need blood supply from neighbouring adjacent bone, therefore, if the implant is placed too buccally, graft will not take place 4. Did I bury implant deep enough? - gotta be little deeper than normal. I usually aim for at least 4mm below intended CEJ level 5. Biotype - will I have good quality keratinized gingivae upon healing. Sometime, it is more important to have better quality tissue than weather you have bone or not. Whether you get bone on the buccal or not does not affect your stability of implant; however, longevity of esthetics will depend highly on tissue quality (CTG - good idea) When using allograft as the only source of bone augmentation in such case, my preferred choice of bone is usually small particle sized cancellous bone material. Large granules dont seem to adapt nicely to thread surface. I think this case may turn out good, after all. ^^ YES, I would like to see the radiograph as well. Thx.

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Bernard Jin Replied at Sat, May 21, 2011 7:29 PM

If all is going well, leave it 6 months + before returning to open the site. If you lose primary closure, you might need to consider aborting the case. From what you reported, it sounds like you're on the right track. Good luck!

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Bernard Jin Replied at Sat, May 21, 2011 7:24 PM

Hi cl, Thanks for your post. Your question is a very important and valid one! Many of us have asked this question one time or another... I think what you did may work. You found that the allograft done by the previous dentist (in conjunction with the extraction) didn't take. By that, I assume you noticed (significant granulomatous tissue within) in the graft material & that it had not turned into any level of bone? If you properly debrided the site (which would reveal the lack of buccal wall), and got the graft site to bleed (blood source of osteoconduction), then it may well work. You reported getting 35 ncm on the implant torque. That's good. Then you placed another allograft into the site. Also good. Placing a CTG over the allograft and then getting primary closure. Good. bottomline - sounds like you're on the right track. I would monitor the graft site with periodic radiographs or small volume scans. If the primary closure remains closed and healed, then you can expect success. BUT - please ensure that the allograft is not under any trauma or stress or movement. If trauma/physical stress/movement is exerted onto the graft, it can fail. With the periodic radiographs to evaluate the bone changes, may I recommend every 8 weeks + or so. You should be able to monitor the increasing level of calcification at the graft site. I have performed this procedure many times. So long as the tenants of graft blood supply & immobilization are adhered to, it should work. Do you have a radiograph or photograph that you could post? I'd like to see it if possible. Please keep us in updated on the progress. Oh... what should we be looking for 'when it's time to bail out?' - prolonged unexplained pain, swelling, purulence, signs of inflammation long after the soft tissue has closed, fistula, etc. You get the message. If none of this props its head up after 6 - 10 weeks, you're probably on the right track to healing. Whenever I do this, I now incorporate PRF into the mix. For 2 reasons, WBC to mop up any residual infections. Platelets WBC & GFs to facilitate wound healing and hard/soft tissue development. Hope that helps! - Bernard