Dear colleagues, welcome to this short lecture. I'm happy to discuss with you implant selection. In the first slide you see a large number of implants, and when we want to choose implants we have a number of decisions we need to make. So clinically from this large palate, the question is which implant type should I use in which clinical situation? Let’s go in to some basics first. On the right side, you see a so called two-piece implant which consists of the endosseous part of the implant. At the left side you see a one-piece implant, you see that the transmucosal part is integrated into the entire implant so the endosseous and the transmucosal part make up the implant itself. What does this mean? Here you see the bone level, the two-piece implant stops at the level of the bone and the one-piece implant reaches through the soft tissues to a level where we can see in the oral cavity. I also indicate a reconstructive margin with these blue lines. Reconstructive margin at the two-piece implant is at the level of the bone where as at the one-piece implant, it's 1mm, 2mm, or 3mm distant from the bone. What does this now mean for clinical use? Two more important words we need to define. You see an implant on the left side and you see the flap close at the right side, and here the flap is sutured to cover the implant completely, this is termed submerged healing, so the implant is submerged underneath the soft tissues. Here the flap is sutured allowing the implant to penetrate into the oral cavity. You see the flap raised on the left side and you see the flap adapted around the neck of the implant on the right side, this is called transmucosal healing. Submerged healing is preferred when soft tissue borne temporaries are used. Here, two-piece implants are preferred. The reason being, it's easier to cover the implants with the soft tissues, and thus avoiding a removable temporary to transfer forces exerted onto the temporary onto the heads of the implant, and thus prevent osseointegration from occurring. Additionally submerged implant is preferred when later soft tissue interventions are planned. Here again two-piece implants are preferred in situations which are usually for esthetic nature. Two-piece implants are preferred in the esthetic zone because they allow more flexibility for shaping the emergence profile. Here you see a two-piece implant on the left and a one-piece implant on the right side, and marked again, the reconstructive margin. Now we see the distance from the reconstructive margin to the soft tissue margin on the left and the right side, and you immediately see that with the two-piece implant there's a larger distance available which allows more flexibility. Let me illustrate this with the image on the left, you see an implant in site two, the yellow circle indicates the top end of the implant, these dotted lines indicate the form of the tooth which needs to be reconstructed, which of course is identical to the tooth adjacent to it. You can also transfer these two dotted lines on the right side of the image. If I now soon propose an implant, you will see that the yellow lines indicate the distance available to form this so called emergence profile. So here two-piece implants are preferred. They allow more possibilities for soft tissue management, increase the prosthetic flexibility. On the other hand one-piece implants are indicated for transmucosal healing when straightforward procedures are preferred. Here you see a mandibular posterior area, flap is raised, an implant is placed, and the flap was adapted around the neck of the implant. What about implant length? Very obvious, short implants are placed when the bone height is of low height. As you can see on the right side the radiographic image, on the left side the clinical image. What about implant diameters? There are some implants that are allow smaller diameters than standard implants. Narrow implants are placed in narrow spaces, very obvious. I have so proposed the X-ray, so you see two narrow implants with narrow reconstructions for lower incisors. What about cylindrical versus tapered implants? A cylindrical implant on the left, a tapered implant on the right. The rationale for choosing tapered implants or choosing this design is that they usually have denser thread distribution, the threads reach closer to the apex, they are more congruent with the bony bed, and thus all these factors together improve primary stability. So tapered implants are placed into extraction sockets because they show improved contact in the bony walls of the alveolus. This is true in anterior, as well as, posterior sides. Let me conclude what we've seen regarding implant selection. Two-piece implants are used for submerged healing, they're used to improve soft tissue management, and they are used to improve the prosthetic flexibility. One-piece implants in contrast are used for transmucosal healing, and they are used to simplify prosthetic protocols because the implant shoulder is located close to the mucosal margin. Conical implants improve primary stability due to the thread design and implant form. Diameter reduced implants at sites with reduced gaps and for minimally invasive surgery. Thank you very much for your kind attention.
