Submerged vs non-submerged
- Minimal inflammation and movement of implants are critical to osseointegration.
- A non-submerged implant placement may imply early loading, shorter treatment period, and less patient morbidity with one surgical procedure only.
- Poor primary implant stability implies a submerged implant placement.
Oral endosseous implants are successful even long-term in the single-tooth situation. At insertion the primary implant stability is obtained by mechanical fixation. The secondary implant stability will result from osseointegration, a process characterized by the development of an intimate bone contact with the implant surface. The direct anchoring of bone to the implant predicts the clinical success of the implant. Inflammation of periimplant tissues and/or movement of the implant impair the osseointegration process. To minimize the risk of impaired osseointegration historically it has been recommended to insert the implant into the bone (submerged implant) and to allow for submerged healing of 3-6 months in the lower and upper jaw, respectively. After that time, during a second surgery, the implants are uncovered.
Figure 1: The principle of submerged (left) and non-submerged (right) implant insertion
Subsequent clinical studies have shown that the use of non-submerged implants reached similar long-term success as submerged ones.
The treatment concept of non-submerged implant placement enables the possibility of early implant loading, one surgical procedure only, and thus a reduced treatment period for the patients. In the single-tooth case, a non-submerged implant/healing abutment may be protected from premature occlusal preload by adjacent teeth.
Figures 2-5: Placement of implant and healing abutment in lower right second bicuspid region according to the non-submerged concept
Submerged implant placement is still advocated in conditions of compromised bone quality, which does not allow a sufficient primary stability at insertion.
Figures 6-8: Placement of implant and cover screw in upper right first bicuspid region according to the submerged concept
Table 1: Clinical differences between the submerged vs. non-submerged implant insertion protocol.