Graft Resorption: What are Normal Limits?

I had the same case as you few days ago, and i was ready to ask the same question as you, i used the Beta Tricalcium Phosphate (RTR-Septodont)for the first time in a left external sinus lift, lifted around 12mm with it...at the implant placement i am still having 6-7 mm of graft but with with a very good density and my implant placement was somehow hard while drilling... I was a Bio oss autogenous bone user...no idea about BTCP...Let's wait for the expert answer...

Anon and Dr serge, I myself am not a big fan of TCP. You will find some on these boards with research and financial interest in TCP tell you its the next best thing to sliced bread. Most people are throwing the TCP out and not using it in Gem 21. They are mixing the PDGF with real bone graft material rather then the TCP. What you are reporting is actually not an uncommon finding with sinus grafting with TCP. TCP is very round in consistency almost like Bee Bee's. So when you put it in the sinus an immediate post op pan will show optimal grafting hieght like Dr Serge example of 12mm post op, but over the next several months the material begins to move and settle (gravity) and gives the loss of graft hieght that you are describing. Thats why Dr Serge had 6-7 mm of hieght after healing. Im simplfy it some, Im sure there is resorption as well. I suggest if you want to use TCP you mix it with PRP which will act like a glue to help decrease the loss of graft hieght based on the consistency of the TCP product. You will still lose hieght even with PRP. The best advice I can give is switch to another graft material and compare the results. Most of the literature shows that TCP is: An inert biocompatible fill material which serves as a nidus or scaffold for bone formation TCP resorbs very slowly and unpredictably over a period of years rather then months. TCP for defect fill next to a tooth usually results in a mixture of bone, osteoid, and fibrous encapsulation and not true regeneration as seen in the Bowers DFDBA study’s TCP usually results in healing by a long junctional epithelium. My advice to anyone doing sinus lifting review Wallace or Delfabrio articles (Meta-analysis) they give you vast knowledge on sinus grafting. In my practice I use mineralized products for sinus lifting which is either Lifenet FDBA, Puros, regereform, or Bio-oss. Hope thats helpful

Having used tcp products exclusively for the last 4 years in sinus lift procedures we have noticed less repneumatization than with irradiated bone.the newer tcp products have the ability to set hard thus reducing graft loss and there is a dramatic reduction in post op pain experienced by the patient , not even a nurophen the followimg day, possibly due to reduced foriegn body response. All the materials have benefits and frailties but must be utilized correctly to achieve the desired results.5 year core samples recently done have show remarkable results with tcp in bilateral lifts as to irrradiated bone. Sure there is significant research in allograft,zenograft and autogenous sinus materials but there is a future in these materials but techniques are vital. The closure of the window is an important area to prevent soft tissue ingrowth, these newer products do that without a membrane thus allowing the periosteal blood supply to aid the graft site yet prevent soft tissue ingrowth. This could be your issue as in my experience there is hardly any or no bone height loss using tcp in the sinus compared with the results of the previous 6 years using allograft materials.

TCP has no ability to produce bone. With the use of this material, you are asking the patient's body to do all the work. I would suggest to use a material that is capable of regereration to living bone. Also, with the use of a high Ca material, the osteoclast must resorb the material before the the osteoblast can replace the graft material with living bone. Synthetics will not produce living bone, it only allows bone to grow upon the graft material. Don Callan

Don, What material do you currently use? Are you using a composite of several materials?

I have done some research about Beta TCP and it seems that the product resorption can not be expected as other products...it may resorb very fast or too slow depending on many factors...the resorption may be due to the cell phagocyte but may be also due to the body fluid...so i think when using it we should use it as thick mix and set hard so that it do not go fast...after all what i read i think it's a very technique sensitive product...for me better switching for something else or mixing it with bone or another product...

I think that i am not in good relation with the BTCP...:) i just opened a flap today to place implants on the left upper posterior side where i have done an external sinus lift 7 months ago using the Beta TCP. the external sinus lift wasn't so bad, a small perforation of around 1mm, put half of a membrane, grafted with BTCP and the other half was put on the lateral window... Before re entering the radiograph showed me a dense graft but like the other case i mentioned previously around 40% of resorption...I was expecting a dense graft inside but when i opened my flap the lateral window still containg TCP that part of them was loose and can be removed with a curette...drilling was like putting an implant into cheese...drills were removing TCP with them and the TCP was loosening like wet sand...To avoid loosing the stability of my implants i drilled only to 8 and 10 mm with my final drills and put 2 12 mm implant(Zimmer Dental)... Is that always the case with TCP?Should i wait longer before placing my implants?IS that density of graft means a future failure of the graft? Should i have done Better than what i have done in my surgery?

I did my thesis on B TCP years ago and I made my own TCP. In the process, I studies all types of TCPs and I understand their biologic behavior very well. TCP in any form is highly resorbable and all the company jargon apart, there is really no form of TCP that stays patent to keep pace with bone formation. If you use only TCP, you will get reduced bone volume primarily due to the resorptive unpredictability of the material. TCP is also highly sensitive to the wound environment and can have even have unpredictable resorption rates. Even pure phase versions of the material cannot control this. With purephase TCP, you can even see very very slow resorption on occasion leading to residual graft that compromises bone density. TCP still has advantages though. When mixed with another calcium phosphate ceramic like HA, it can result in a material with a varied resorption rate in the composite graft that has the best of both materials. Straumann's Bone Ceramic is an example of such a material. The TCP resorbs in the early phase allowing tissue invasion and the HA resorbs more slowly allowing bone formation to replace it. Of course the type of HA or TCP matters too, you can vary the crystallinity of both materials and get varying rates of resorption and even total non resorption (at least with HA). Having said all this, it does not make sense to place such materials in the sinus in isolation. You will get bone, but only 6-9 months or more down the line and in lower quantity and density. It is good to mix such materials with autogenous bone or mineralised bone for better results. After all, getting bone in the sinus is not just about creating it in volume but in good density as well.

Firstly the body does all the work anyway in bone creation and we are fortunate to be working in such an efficient compliant medium. Mixing with autogenous bone was something we did initially but have not done in the last 3 years or so and seem to have better results as a consequence. A 5 year core sample study done here recently (Mcgee etal) has show significant increase in density of the bone created by the body when utilizing TCP as compared to Allograft materials in a bilateral case. I have hundreds of photos utilizing these materials and have presented cases showing 1 step sinus lift and placement in 1 to 2mm of bone then loading at 6 months (in full occluion) and then showing a further increase in density at 1 year loaded.The most impoetant aspect is that the materials do resorb so what you see on the X-ray is bone not HA. In europe there are many of these TCP based materials ,but the ones that set are the future as stability of the graft is another very important feature. Our collegues in the orthopedic and spinal surgical areas have done a lot of work with these materials and results are impressive but sure the ideal material is the future goal whether it is BMP or Stem cell orientated

Dr P, I am still using FDDB; IT WORKS. I do not use any synthetics.

To anaon Original post Can I confrim that you are using Cerasorb when you say TCP Its not quite the same thing Cerasorb(TCP) is in spheres Regular TCP is a powder that you mix with saline not intended for use with sinus graft Cerasorb actually works well I agree with the posts previously regarding technique if Cerasorb is pack too tight this causes the speres to get crushed ..thus lose scffold and volume effect I often use Cerasorb with FDBB works well SS

Dear friends! try it with easy graft!

What ever discussed here does not seem to be getting any where and it seems we are running in circles. Every thing works except that which you are not using! Put any thing into the sinus every thing turns into dense bone! Can we get some independent studies here? Please mention names of peer reviewed Journals here.

When using B-TCP, our technique will play an important role in the success of the graft and so will the TCP used. You certainly want to stay away from the rounded, bee-bee shaped TCP materials, which will take too long to resorb. I use Cerasorb, which comes in a granular shape - very porous, allows ingrowth & integration of new bone. Keep in mind not to crush the TCP when placing it (technique). In the sinus, I use 80% Cerasorb mixed with DFDBA and a very small amount of Dynagraft (expensive). I am waiting 4-5 months and experiencing great success with no bone loss. I too believe B-TCP (Cerasorb) & BMP's are the future and should be looked at more closely.

I think the concept of bone grafting is changing espacialy in the area of sinus ,reviewing the recent studies show that sinus area without bone grafting still we got bone formation from the clott transformed into bone like bone formation at the extraction socket,even allografting material may be the reson of delayed bone formation.I know that any new concept is not easy to accept & most well refuse it.also there is alot of points to discuss,but I added this comment to open the door for a different way of thinking

what if i use plaster sinus by ghimas ? ant experience using that one ?

Does anyone here have any experience with 'Ossifi' from Equinox technologies? It is "Ossifi is a porous biphasic bone graft material with exclusive features,an extensively researched and evaluated combination of Hydroxyapatite and ß-tricalcium phosphate in a 70/30 ratio.Ossifi is a synthesized combination of hydroxyapatite and ß-tricalcium phosphate creating a new molecule with new characteristics. This molecule remains constant throughout the whole process of resorption and bone formation, reducing the risk of cavities of fibrous ingrowth. Moreover, Ossifi has a bioceramic matrix that is extremely biocompatible and highly osteoconductive. The exceptional purity of the raw materials used in the production of Ossifi and its highly interconnected pores with 90% porosity, make it one of the worlds finest osteoconductive biomaterials." I just copy pasted this from the company website. Does this material set? Can it be used like Cerasorb? is 70:30 combination of hydroxyapatite/tcp a good idea? Is it "good enough?" Does any one have any experience about "Ossifi"?

Why does the ideal bone graft easily resorb? Is there any idea?

It is normal for this resorbtion to take place Robert Marx showed in 1989 that the prime issue of autogenous Particulate Corticocancellous Grafts was its Compression (hence Particulate Compressed Cortico Cancellous Bone Grafes or PCCBs )and that Oseoblast/presursor increased cell density in phase 1 bone is critical in preventing resorbtion in phase 2 remodelling. In his studies he showed circa <10% loss of insterstitial bone graft loss of volume at 1 year. And Marx did not use membranes. The key issue on graft stability is autologous Cell Density. We will see as technology progesses Bone marrow cell density being a critical factor in volume maintenence augmented by PRP