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Simple Ridge Augmentation:
The Advantages and Disadvantages of Regenerative Medicine vs Cadaver Bone Grafts

Let’s define the terms:
Regenerative medicine is defined as a branch of medicine concerned with developing therapies that regenerate or replace injured, diseased, or defective cells, tissues, or organs to restore or establish normal function and structure.

Regenerative medicine recognizes that the human body is not capable of replacing injured, diseased, or defective tissue without assistance. In order to reestablish normal function and structure, regenerative medicine must introduce a biologically active compound or cells to facilitate the regenerative process.

A cadaver is a dead body.

A corpse is a dead human body from which allograft tissue is extracted.

A carcass is a dead animal body from which xenograft tissue is extracted.

The term cadaver bone grafts can refer to either allografts or xenografts. Since there is no difference in the mineralization process or the type of bone produced by either material, the term ‘cadaver bone grafts‘ will refer to both allografts and xenografts in this presentation.

In this case presentation, implants were placed 8 months after grafting. The surgical procedure of this case was identical to a simple ridge augmentation previously presented and can be viewed through this link: Simple Ridge Augmentation. The previous ridge augmentation case showed implants placed 4 months after grafting. The time difference of both of these cases will allow us to evaluate the process of bone formation and remodeling when tissue is regenerated using the principals of regenerative medicine.
ridge augmentation surgery showing missing bone on the buccal of a knife edge ridge
In the 4-month case above, the only missing bone was on the buccal of a knife edge ridge and therefore the bone graft material was placed only on the buccal, leaving the membrane to lay directly on the lingual cortical bone. As you can see, the buccal bone was regenerated with a minimal amount of residual βTCP particles left in the tissue.

In the this 8-month case, we will see what happens when you graft outside the normal confines of the original alveolar ridge when using regenerative medicine materials and methods.
mandibular pre-op CT scan with inadequate width in bicuspid area and inadequate height in molar area
This mandibular pre-op CT scan for the 8-month case presents with inadequate width in bicuspid area and inadequate height in molar area.
ridge augmentation of pre-op bicuspid area
Pre-op bicuspid area.
ridge augmentation radiograph of pre-op molar area
Pre-op molar area.
Post-op photograph of synthetic dental bone grafted alveolar ridge
Post-op alveolar ridge 8 months after grafting. Day of implant placement.
post-op radiograph of synthetic dental bone grafting site
Post-op ridge 8 months after grafting. Day of implant placement.
ridge augmentation with full thickness flap exposing a d-PTFE membrane
Full thickness flap exposing the d-PTFE membrane 8 months after grafting.
ridge augmentation surgery showing membrane removal with granules visible on the lingual and buccal sides of the alveolar ridge
The first layer of the Teflon membrane was removed, leaving the second layer bonded to the underlying bone. The layer contacting the bone required significant scraping to be fully removed. Note the remaining granules on the lingual and buccal sides of the alveolar ridge.
top and bottom surface of teflon membrane
The object on the right is the top surface of the membrane. The object on the left is a portion of the bottom layer of the membrane that needed to be scraped off the alveolar ridge. The bone appears to fuse with the teflon membrane by what appears to be an osteoid layer.
ridge augmentation surgery with membrane removed and granules visible on the lingual and buccal areas of the mandible
With the remaining membrane removed, the only remaining granules are noted on the lingual and buccal areas of the mandible.
ridge augmentation surgery with 4.2 mm implant in the bicuspid area and a 4.8 mm implant in the molar area
A 4.2 mm implant was placed in the bicuspid area and a 4.8 mm implant was placed in the molar area. The healing abutments were placed at the time of surgery.
ridge augmentation surgery showing βTCP granules on lingual and buccal surfaces
Note the remaining βTCP granules on the lingual and buccal surfaces. Bone growth with complete remodeling of the βTCP particles has occurred in the areas of the mandible where the graft was within the confines of the original mandible. While the βTCP particles have been encased in mineralization on the buccal and lingual of the mandible, no remodeling has occurred.
ridge augmentation surgery showing missing bone on the buccal of a knife edge ridge

This is the 4-month case from the beginning of this article shown for comparison. Since all the pre-graft resorption occurred on the buccal, the membrane was applied directly over the lingual cortical bone. After placing the membrane, graft material was placed on the buccal surface only. This located the graft material within the borders of the original mandible. As a result, the graft material was completely resorbed and converted into vital bone.

One of the limitations of regenerative medicine is that we are unable to regenerate a damaged tissue outside of the confines of the original dimensions of the bone, determined by the genetic code that grew the bone originally. Using regenerative medicine, the best we can do is to regenerate what was lost. The bone on the buccal and lingual of the mandible that contains residual βTCP particles is not normal bone and cannot be relied upon to properly integrate and support dental implants. Cadaver bone grafts do not have this limitation. Cadaver bone grafts are not guided by the genetic control of your patient’s cells and wherever you can obtain mineralization, the graft material will remain. Because cadaver bone grafts never remodel once the mineralization process has occurred, the shape of the bone is fixed indefinitely. This allows creation of mineralized tissue outside the preexisting confines of the patient’s original bone.

An advantage of regenerative medicine, however, is that once the bone has formed, it is normal bone and the newly regenerated bone will integrate to the implant in the area of regeneration. The disadvantage of cadaver bone is that it has never been shown to integrate to the implant surface and the implant is supported only by the basal bone that existed prior to grafting.

Another disadvantage of using regenerative medicine materials and methods is that it requires more knowledge and skill to regenerate normal healthy vital tissue when compared to cadaver bone grafts that produce sclerotic bone, which equates to scar tissue.

Every material has its pros and cons and knowing what you want to achieve with your surgical procedure will determine what material is best suited for the desired result.

Follow the link below to see the step-by-step breakdown of the case presented:

Simple Ridge Augmentation: Step By Step

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