IMPLANTS, GRAFTS, GBR, PDGF
Simply put, teeth need bone to anchor them, and bone needs teeth for a reason to be. When a permanent tooth descends into it's place, bone is simultaneously built up around it. When this natural process is interfered with,you have problems. If a tooth is extracted or lost to trauma, the bone at the site will resorb.
With no tooth in place, but instead impacted in the wrong position, the bone doesn't develop the way it should and you end up with a deficiency of the alveolar ridge, and not enough bone to secure an implant.
The solution to this is to first get some bone in artificially. In the beginning, the logic of course was to take bone from the patient (autografts) where it was considered to be expendable, like from somewhere else on the body. Bone is different in different locations so the most structurally alike bone for an implant would be taken from the chin bone, the zygomatic bone; other locations would be the iliac crest(hip bone). Bone can also be harvested from cows, pigs (xenograft = other species) and dead humans (allograf). Depending opn location you get either membranous bone or endochondral bone.
To get this bone is an extra surgery for the patient with some inherent risks and another wound that needs healing, so research started looking for other options. So now we have a 4 billion or so industry that is continually expanding and evolving. With an aging, osteoporotic and growing population there is a need to repair bone all
over, besides bone missing due to trauma or developmental issues.
And the bone is only part of the story. It's the scaffolding, but it also needs to be nourished and stimulated so that starts up an entire cottage industry of additives to improve the result.
Bone tissue Engineering
Some properties you want in a graft:
osteoinduction = bone morphogenic proteins (BMPs) and growth factors
osteogenesis = the making of the
osteoconduction
vascularisation = blood supply for nutrients in and
As for the bone part there are pros and cons:
PRO CON
Autograf histocompatible Second surgery needed with risks and healing
needed.
Expensive
Limited availability
Allograf histocompatible risk immuno reaction
risk transfer of infection (subjected to to
radiation or freeze-drying to avoid this )
Xenograf
Alloplast Not biological, hydroxyapatite.
With no tooth in place, but instead impacted in the wrong position, the bone doesn't develop the way it should and you end up with a deficiency of the alveolar ridge, and not enough bone to secure an implant.
The solution to this is to first get some bone in artificially. In the beginning, the logic of course was to take bone from the patient (autografts) where it was considered to be expendable, like from somewhere else on the body. Bone is different in different locations so the most structurally alike bone for an implant would be taken from the chin bone, the zygomatic bone; other locations would be the iliac crest(hip bone). Bone can also be harvested from cows, pigs (xenograft = other species) and dead humans (allograf). Depending opn location you get either membranous bone or endochondral bone.
To get this bone is an extra surgery for the patient with some inherent risks and another wound that needs healing, so research started looking for other options. So now we have a 4 billion or so industry that is continually expanding and evolving. With an aging, osteoporotic and growing population there is a need to repair bone all
over, besides bone missing due to trauma or developmental issues.
And the bone is only part of the story. It's the scaffolding, but it also needs to be nourished and stimulated so that starts up an entire cottage industry of additives to improve the result.
Bone tissue Engineering
Some properties you want in a graft:
osteoinduction = bone morphogenic proteins (BMPs) and growth factors
osteogenesis = the making of the
osteoconduction
vascularisation = blood supply for nutrients in and
As for the bone part there are pros and cons:
PRO CON
Autograf histocompatible Second surgery needed with risks and healing
needed.
Expensive
Limited availability
Allograf histocompatible risk immuno reaction
risk transfer of infection (subjected to to
radiation or freeze-drying to avoid this )
Xenograf
Alloplast Not biological, hydroxyapatite.
Implants
First of all: Don't smoke! If for not all the other reasons, dental implants are incompatible with smoking
It consists of 3 parts:
screw
abutment
crown
To make the hardware stick you need GBR and PDP, see below.
screw
abutment
crown
To make the hardware stick you need GBR and PDP, see below.
GBR = Guided Bone Regeneration
Post-extraction crestal bone resorption is common and unavoidable which can lead to significant ridge dimensional changes. To regenerate enough bone for successful implant placement, GBR is often required. GBR is a surgical procedure that uses barrier membranes with or without particulate bone grafts or/and bone substitutes. There are two approaches of GBR in implant therapy: GBR at implant placement (simultaneous approach) and GBR before implant placement to increase the alveolar ridge or improve ridge morphology (staged approach). Angiogenesis and ample blood supply play a critical role in promoting bone regeneration. (1)
Post-extraction crestal bone resorption is common and unavoidable which can lead to significant ridge dimensional changes. To regenerate enough bone for successful implant placement, GBR is often required. GBR is a surgical procedure that uses barrier membranes with or without particulate bone grafts or/and bone substitutes. There are two approaches of GBR in implant therapy: GBR at implant placement (simultaneous approach) and GBR before implant placement to increase the alveolar ridge or improve ridge morphology (staged approach). Angiogenesis and ample blood supply play a critical role in promoting bone regeneration. (1)
PDGF = Platelet Derived Growth Factor or (Platelet Rich Plasma)
The efficacy of this treatment is not yet uncontroversial. Insurance doesn't pay for any of it.
The graft/material/barrier created space is filled with the blood clot which releases growth factors (e.g., platelet derived growth factor) and cytokines (e.g. IL-8) to attract neutroophils and macrophages. The clot is absorbed and replaced with granulation tissue which is rich in newly formed blood vessels. Through theses blood vessels, nutrients and mesenchymal stem cells capable of osteogenetic differentiation can be transported and contribute to osteoid formation. Mineralization of osteoid forms woven bone, which later serves as a template for the apposition of lamellar bone. The transformation of primary sponge work would eventually constitute both compact and reticular bone with mature bone morrow. These events occur 3 to 4 months post surgery. (1)
The efficacy of this treatment is not yet uncontroversial. Insurance doesn't pay for any of it.
The graft/material/barrier created space is filled with the blood clot which releases growth factors (e.g., platelet derived growth factor) and cytokines (e.g. IL-8) to attract neutroophils and macrophages. The clot is absorbed and replaced with granulation tissue which is rich in newly formed blood vessels. Through theses blood vessels, nutrients and mesenchymal stem cells capable of osteogenetic differentiation can be transported and contribute to osteoid formation. Mineralization of osteoid forms woven bone, which later serves as a template for the apposition of lamellar bone. The transformation of primary sponge work would eventually constitute both compact and reticular bone with mature bone morrow. These events occur 3 to 4 months post surgery. (1)
Here's an article critical of the hyperbole without any conslusicve evidence from 2016: Bench to Bedside: Platelet-rich Plasma - How Do We Adequately "Untranslate" Transitional "Breakthroughs" in an After-Market Setting? (2).
EMP = Enamel matrix protein
Emdogain®
Emdogain is an EMP. According to the Straumann®(3) website it is a mix of enamel matrix proteins that, when applied to a clean tooth root surface or oral wound, form an extracellular matrix that stimulates cells and processes that are fundamental for periodontal regeneration and soft tissue healing.
It's been used since 1996. It is applied as a gel. It comes from developing embryonal tooth buds from fetal pigs. Amelogenin is the main protein and the one responsible for tooth development. It is used for gingival recessions, and bone defects.
Emdogain is an EMP. According to the Straumann®(3) website it is a mix of enamel matrix proteins that, when applied to a clean tooth root surface or oral wound, form an extracellular matrix that stimulates cells and processes that are fundamental for periodontal regeneration and soft tissue healing.
It's been used since 1996. It is applied as a gel. It comes from developing embryonal tooth buds from fetal pigs. Amelogenin is the main protein and the one responsible for tooth development. It is used for gingival recessions, and bone defects.
(1) Jie Liu, Kerns D. Mechanism of Guided Bone Generation: A Review. Open Dent J. 2014; 8:56-65.
(2)Potter BK. Bench to Bedside: Platelet-rich Plasma-How Do We Adequately "Untranslate" Translational "Breakthroughs" in an After-market Setting?. Clin Orthop Relat Res. 2016;474(10):2104–2107. doi:10.1007/s11999-016-4992-z
3) Emdogain was a product of the Swedish company Biora, that was bought up by Straumann in 2003.
Davarpanah M, Szmukler-Moncler S. Unconventional implant treatment: Implant placement in contact with ankylosed root fragments. Aseries of case reports. Clin Oral Implants REs. 2009 Aug;20(8):851-6.doi: 10.1111/j. 1600-0501.2008.01653.x. Hi