Alveolar Bone as the Surgical Guide for Early Implant Placement

Early implant placement using regenerative grafting materials that stimulate osteoblast formation and proliferation provides us with many advances over delayed implant placement.

Delayed Implant Placement
In delayed implant placement, the bone is very inactive with few active mineralizing cells. When this bone is drilled, it is essentially asleep. Drilling and placing an implant with a slightly larger diameter damages the bone that provides primary stability. The damaged bone needs to be removed by osteoclasts, which decreases stability significantly to minimal levels at about 2 weeks. Secondary stability is called osseointegration, where osteoblasts form bone on the implant surface and connect this new bone to the surrounding alveolar bone. This process then increases continuously over time, and more rapidly increases about 2.5 weeks after implantation to achieve a plateau level at about 5 or 6 weeks after implantation. The whole transition process from the initially dominating primary stability phase to the finally dominating secondary stability phase takes about 5–8 weeks and secondary stability often does not reach primary stability levels.

Early Implant Placement
In early implant placement, with science-based regenerative materials, the aforementioned process is skipped as the implant is placed in tissue that is filled with rapidly proliferating osteoblasts. Therefore, implant integration occurs in roughly half the time. In early implant placement, you are placing the implant into the healing socket rather than waiting for the socket to heal. You are then drilling out the bone for the implant and then recycle the whole bone removal and bone formation process. In delayed implant placement, it is common for primary stability to be greater than the final implant stability. In early implant placement, the opposite is true and in our experience early implant placement provides a superior level of osseointegration and implant stability.

The following case demonstrates early implant placements.

Preop

5 weeks after extraction and grafting with Socket Graft™ by SteinerBio. At this point, the socket is filled with early mineralized bone.

5 weeks after extraction, the d-PTFE membrane is removed and the site is prepared for implant placement. No flaps, no sutures.

Implant placement at 5 weeks post extraction. Because of the amount of bone loss, this implant is placed in newly formed bone with little to no contact with preexisting bone.
After integration, the patient presents with excellent integration to the collar of the implant. When osseointegration is complete, excellent stability is achieved. One of the advantages of early implant placement is the implant is placed before the sinus floor can resorb, thereby avoiding sinus augmentation surgery.
In the previous case, the socket was filled with newly formed bone and placement into the regenerating socket was simple and quick with no flaps required. However, often after extraction if the original socket is complete, this can complicate implant placement when placing an implant in a socket that is filled with soft bone adjacent to hard bone. In order to take advantage of the original extraction socket, the following case shows how the clinician can create a surgical guide in the extraction socket to facilitate early implant placement.
After extraction, the socket is intact except for a fenestration at the apex of the buccal root. A buccal envelope full thickness flap is raised and a lingual split thickness is raised to receive the d-PTFE membrane. At this time, the socket is easily visualized and the decision was made to prepare the socket for a 4.2 x 11 mm implant in the area of the interradicular septal bone.
Rather than opening an implant surgical kit, the implant drills are kept separately. These drills are actually used drills from kits where we have replaced the drills with new drills. Little concern needs to be given to the standard protocol for implant placement because it will be 4 to 6 weeks before the implant will be placed in this site. A standard latch type slow speed drill is used to create the osteotomy.
Preparation of the osteotomy is very easy as you can visualize the entire process with the open flaps for the membrane. The osteotomy in this case was created with the standard sequence of drilling up to and including the final drill for a 4.2 diameter implant. The osteotomy is located in the interradicular bony septum. At the apex of the buccal root is soft tissue in the area of the fenestration.
At day of extraction and grafting, the socket is filled with Socket Graft™ by SteinerBio. The implant is then scheduled for placement 4 weeks after extraction. At that time, the membrane is removed. The prepared socket functions as a surgical guide for a quick and easy implant placement, with a healing abutment placed level with the gingiva. No incisions, no flaps, and no pain meds needed.
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