Few surgeons have had more experience with implants than Dr. Bertil Friberg. He studied with Professors Ulf Lekholm and Per-Ingvar Brånemark and has been a fixture at the Brånemark Clinic in Gothenburg, Sweden, since its inception.
A respected educator as well as an experienced clinician, Dr. Friberg shares some of his insights concerning implant-based treatment in the following Questions and Answers.
In a situation of limited jawbone volume distal to the canine tooth in the maxilla — that is, sparse volume for two implants due to an anteriorly-extended maxillary sinus — which implant site should I prepare first?
Dr. Bertil Friberg: It would probably be a good idea to prepare the most distal implant site first (the one in the second bicuspid region). Preferably, this work should be carried out parallel to the anterior wall of the sinus, heading towards the canine, thus allowing for an implant of good length. Figures 1a and 1b (shown in gallery below), courtesy of Dr. Alberto Turri, illustrate just such a situation.
Allowing the longer implant to be placed with mesial inclination in this area — where the jaw bone most often has less volume and density and the chewing forces tend to be higher — makes sense from a load-bearing and longevity point of view. In this configuration, the mesial site (in the first bicuspid region) provides less height, but enough room to accommodate a short implant.
The radiograph in figure 2 (below) shows a situation in which the opposite has been done. As you can see, placing the short implant in the distal site, where there is less bone volume and lower density — as well as the aforementioned higher chewing forces — constitutes a less appropriate solution and a rather less certain long-term prognosis.
If I were to run into excessive bone loss around one or several implants related to infection, what would you advise?
Friberg: A program of conscientious hygiene control, sometimes subsequently including explorative surgery with bone plasty, may be the solution to the problem. However, before beginning such a course of treatment, you should be aware that a successful outcome is in no way ensured.
The case to the left illustrates an alternative plan of action. Here the clinical team plans to replace the lower right canine and both lower right bicuspids with implants (figures 3a and 3b below). Instead of producing a three-unit prosthetic construction supported by two new implants and the old one, which has been adversely affected by bone resorption, the l-year-old implant (figure 3c) will instead be replaced with three new ones. The tool of choice for such a removal procedure is a trephine drill (figure 3d), available in various diameters from Nobel Biocare. The final image below (figure 3e) shows the surrounding bone after removal, which presents a fresh site for continued treatment.