As a non-surgeon I often listen in confusion to the debate about whether to place implants with or without a flap. One of the biggest reasons that I have heard in support of a flap is the ability to see the surrounding bone. The ability to visualize what is happening has always been important in restorative dentistry, so it makes sense that it applies to surgery. On the other hand we have 3D cone beam imaging that shows us the osseous anatomy clearly, so I can see that in the days before cone beam imaging the need for actual visualization was much greater than today.
The move toward flapless implant placement has been driven by the desire to preserve the buccal soft tissue esthetics as much as possible. This is especially critical when working in the anterior esthetic zone. The position of the free gingival margin on the facial is driven by the position of the bone, both facial and interproximal. There are numerous aspects of treatment planning that help us predict the risk of recession of the free gingival margin and negative esthetic outcomes.
Beyond treatment planning exquisite surgical treatment, tissue management and implant placement are key factors in esthetic success of an anterior implant. One of the surgical decisions is whether or not to place a flap. Critical to this decision is understanding where the blood supply to the buccal plate comes from, which is required to optimally maintain it:
- Periodontal Ligament
- Endosteum (marrow)
- Periosteum
The PDL disappears at the time if extraction. Most of the time there is little to no endosteum or marrow space in the buccal plate due to the architecture of the bone. So the only remaining blood supply is the periosteum, which is subject to degradation when flap is laid. Flapless surgery leaves the periosteum untouched and optimizes the chances of maintaining adequate blood supply to the buccal plate of bone, thereby optimizing the healing potential.
There are pluses and minus of flapless placement, when we look at the work of Joseph Kan, we see that there is significant buccal resorption a couple of years down the road. We are trying to compensate by placing a connective tissue graft on the buccal at the time of placement. In that case, we are pouching the buccal tissues. While this may give us thicker tissue, it does compromise the vascularity. When we look at the work of Buser and Belser, they advocate a delayed immediate approach with simultaneous GBR. This approach has show great esthetics as well. Raising a flap isn’t just about visualizing the bone, it can give us access to be able to better compensate for resorption of the buccal plate in the future. The key point isn’t that flapless is better or raising a flap is superior, it’s how the surgeon handles the soft tissue.
hence the need for PET technique.