Maximizing Esthetics and Function with Immediate Implant Placement
A guide to ensuring stability and ideal positioning
Jason Kim, DDS
The concept of immediate implant placement has taken on a new role in the treatment planning of dental implants. With this approach, it is no longer a prerequisite to let an extraction site heal for 4 to 6 months before placing a dental implant. Provided that certain criteria are met, implants can now be placed at the time of extraction. Original protocol was such that in order for dental implants to be successful, they had to be submerged for a period of time to achieve osseointegration.1 There is now evidence to support the fact that implants can be placed at the time of extraction and both achieve osseointegration and maximize esthetics and function.2,3 There are benefits to being able to simultaneously extract a tooth and place an implant. There are fewer surgeries involved, it takes less time to complete the case, and hard and soft tissues can be preserved. Along with the benefits also come some risk factors. Some of these may include but are not limited to: implant failure, infection, bone resorption, and soft tissue recession.4
In cases of immediate implant placement, it is imperative to have a prosthetically driven treatment plan. The final restoration must be determined prior to having any type of surgical treatment. If a prosthetically driven approach is taken, the type of restoration will dictate the treatment flow for the case. Implant position will determine whether a screw- or cement-retained restoration can be fabricated.
A screw-retained restoration has its advantages in that there is always retrievability. The other advantage is not having complications related to over-retained cement in the gingival sulcus. For a screw-retained restoration, the implant placement must be in a lingually inclined position. That position must allow the screw access hole to emerge from the cingulum of the tooth to be restored. The slightest change in angulation negates the ability to have a screw-retained restoration but can still be restored as a cement-retained restoration.5 Depending on clinician preference, the ability to have a screw- or cement-retained restoration is dependent upon appropriate implant placement.
Patients today are not only asking to complete their cases faster, but implant companies are claiming to reduce treatment times with newer implant technologies and improved surgical techniques.
Immediate implant placement can be implemented provided that specific parameters are met. When planning for immediate implant placement, the first criterion that must be met is primary stability. To achieve primary stability, the implant must extend beyond the apex of the socket by 4 mm. Anything less than this may compromise the initial stability. The implant must engage bone beyond the apex because the extraction socket dimensions are going to be much larger than the size of the implant being placed. In cases involving the anterior esthetic zone, one must be wary of the tissue remodeling that will occur following tooth extraction. The result is more buccal bone resorption than the lingual wall.6
There are specific guidelines that must be met for one to be able to extract a tooth and place an implant at the same time. Figure 1 and Figure 2 show a preoperative radiograph and photograph of a failing tooth that is periodontally involved. When placing an implant at the time of extraction, care must be taken to remove the tooth as atraumatically as possible. The main purpose of this is to preserve as much bone as possible, especially the buccal plate. Any fracture of the buccal plate, especially at the crest where it is thinnest, can compromise the intended result with implant placement. This can be done utilizing periotomes, elevators, and piezosurgery technology, among others. The socket is then debrided to eliminate any infection, soft tissue, and granulation tissue. Planning should have already involved evaluating whether a thick or thin soft tissue biotype is present. A thick biotype will promote long-term stability as well as allow for flapless extraction and implant placement. Thin biotypes are more prone to recession following healing, which allows the implant to show through, compromising esthetics.
3D Implant Positioning
The next phase is to begin the osteotomy preparation. In the anterior esthetic zone, it is important to engage the palatal wall of the socket. This must be initiated approximately two thirds of the way down the socket.7 Figure 3 shows the direction of the osteotomy in relation to the palatal wall. This will ensure that the implant does not perforate the thin buccal wall and engages the denser bone of the palatal wall. In posterior regions, it is best to stay slightly more lingual and to go beyond the apex of the socket to ensure adequate initial primary stability.