Can someone please explain what ridge parameters you have to have, to place a bone block vs particulate bone and a membrane for ridge augmentation. Is a ridge less than 3mm (say 2.7mm) buccopalatally indicated for a bone block only? Or do both work? Thanks
timcarter comments:According to Dr. Michael Block who has been well published in the OMS grafting literature he has not performed a block graft in over 10 years except for resident training. In my experienced having been a practicing periodontist for nearly 20 years I have never seen a situation that requires a block graft vs. particulate and conventional GBR. IMHO it is purely operator preference and anyone that claims superiority of one modality over the other is most likely expressing a personal bias. I can not seem to justify the risk of doing an additional surgery to harvest the block graft when there seems to be no real benefit.
bonegraft comments:Do you use PRF with GBR?
timcarter comments:I think it doesn't matter as both block graft and particulate work.... the issue lies in how do we as clinicians justify one approach over the other. For me there is less chance of post operative complications when a single surgery is done to utilize a particulate and to date no real conclusive evidence exists to prove superiority of one modality.
ulrhet comments:Simply dont do block graft. Its predictibility is very very poor. For horizontal defects, a GBR is the gold standard
bonegraft comments:And if there is also some vertical defect?
gregkammeyer comments:I did my research on block grafting, at Loma Linda U, with Carl Misch's guidance among others. I found that block grafts are technique sensitive more than GBR and don't revascularize quickly. When you look at an expert's grafts like Dr Mike Pikos (whom I highly respect) you'll note that many of his blocks look white when the flap is laid for implant placement...not fully vascularized. In my experience a number of beautiful cases I've done, went South as the years passed....bone resorption. I too have abandoned using blocks.
GBR also is technique sensitive and when done well can get terrific results esp for horizontal defects. Tim is right; for these defects neither is superior, with cortical intra oral block donar sites versus GBR. Iliac crest grafts with Stem Cells is a whole different bag, and certainly works very well for larger defects.
Get Dr Istvan Urban’s book on GBR. He has jumped to the fore front of current GBR techniques, including using collagen membranes. He does use 50/50 autogenous bone scrapings which can involve a second surgical site, which isn’t a big deal. I find PDGF/GEM 21 with allograft very effective and will often use TiMesh when the defect gets bigger. Good luck!!
bonegraft comments:Thank you. what about block graft and particulate, PRF, collagen membrane and PRF on top? I.e. autogenous and triple membrane for a single tooth resorbed ridge?
drdangober comments:This is a great question for discussion! I personally do not have experience with block grafts and am not particularly attracted to the idea of harvesting such a large amount from a secondary site. BUT I have seen some very impressive results from colleagues with the "khoury" technique which seems to be somewhat of a merge between block grafting and particulate grafting. In the end every case comes down to the same principles of GBR: flap management, blood supply, space maintenance, barrier function etc. A great article for review of these principles is provided by Wang in 2006 (I'm happy to send it directly if you are interested). When it comes to vertical GBR and non-space maintaining defects, I can see the value of employing some form of a block graft to overcome that limitation but the problems that everyone else listed on this board are real considerations.
bonegraft comments:Thank you for this Dr, Gober. Your post makes a lot of sense. I encounter single missing centrals where there is a thin ridge buccopalatally of
valsharma comments:Agree with Dr Gober, this is an excellent question for discussion. As an OMF surgeon, I routinely use block grafts for a variety of circumstances but especially for large alveolar defects following resections where primarily there is a considerable vertical component to the defect. I have employed various modalities (autograft cancellous/alloplast/xenograft with Titanium mesh, alloplast blocks, BioGlass, distraction osteogenesis, free corticocancellous blocks and vascularised free tissue transfer- all with and without PRF) for augmenting these defects to allow for implant rehabilitation (amongst other things). In keeping with the original question, I've split ridges
gregkammeyer comments:Dr Valsharma, I too have had a number of block cases that still look great. For me, the problem with ramus and chin grafts is that they are mostly cortical bone. If I perforate it, as with corticotomy, then it has much more bone turnover. If you do enough of them, and like the procedure, you likely get decent results. Given that this web site is more for the novice surgeon, I suspect that GBR would be more forgiving, esp with current generation of membranes that will stand up to tacs and can be stretched yet hold shape well. For me, I have also done almost all of the other grafts you mentioned including tibia, Khoury technique, Lazerus graft, ridge splits and DO (No vascularized bone grafts). I agree that there are alot of factors to consider when choosing bone regeneration.
After 37 years of implant dentistry, I find the GBR gets faster and more complete vascularization, and I am most often satisfied with them. Certainly like Dr Pikos, we all find different procedures that we like doing, get good at and refine over the years. I note Mike is lecturing more on TiMesh/BMP now than before, yet it may be like my practice, he treats the elderly. More risk of morbidity with them than young people. I personally never found block grafts all that satisfactory long term and note that VERY few lecturers are still promoting them the way we were 15-25 years ago.
To address the side question that the original posting dentist BONEGRAFT asked me, it’s the slow bone turnover of the cortical bone that I don’t like about blocks. Yes, L-PRF will help angiogenesis, as will PDGF, which I use routinely. Yet the density of the bone block is the primary issue I have with block grafts. If you want to put a collagen membrane over any graft, use one that resorbs in 3 months so you get better vascularization. Unfortunately the L-PRF lasts 2 weeks and the PDGF lasts a few days. Small block grafts have the challenge of where do you put the screws? No matter what you do, I applaud your asking questions. Dentistry at it’s heart is still an apprenticeship and learning is ongoing.