Functional Load in Oblique Bicortical Implants: Parasinusal Implants and Palatine Implants
The history of intraosseous implantology, as a whole, begins with the introduction of the Formiggini screw. Single-piece implants were subsequently derived from titanium bars. The intrinsic function of the emerging stump was immediate loading. The great stability of the implant in the bone thus demanded was eventually achieved by means of the self-tapping screw and bicortical support. Oblique implants were subsequently adopted to make the best use of the bone available and to avoid zones at risk, such as the maxillary sinus and the inferior alveolar nerve. Angled stumps on osseointegrated 2-stage implants were also described in the literature. There has since been a switch from sunken to single-stage implants in view of the usefulness of immediate loading. Recent articles have illustrated the use of inclined, nonbicortical implants; these are still placed in the spongy bone.
Photos of instruments.
Figure 2. The blue line shows the mean of the stresses imposed by 5 long cylindrical implants subjected to loads of 0 to 450 N at zero inclination. Modified from Calderale et al.7 Figure 3. Application of the load at 45° greatly reduces the stresses imposed by the long implants. These stresses are also lower than those imposed by short implants of the same type (red line). Modified from Calderale et al.7
Figure 4. No. 13 oblique and bent bicortical implants. Figure 5. Parasinusal, palatine, and mandibular implants. One (left) is straddling the inferior alveolar nerve. Figure 6. Computerized tomography scan 03. Figure 7. Axial projection showing the tips of the implants in the basal bond lamina. Figure 8. Computerized tomography scan 36. Figure 9. Coronal projection: 2 oblique implants bent along the alveolar and palatine processes of the maxilla.
Follow-up after 8 years. Slight accentuation of bone reabsorption of the right mandibular distal implant.
Figure 13. The metal-ceramic implant-prosthesis. Figures 14–16. No. 9 oblique bicortical implants. One of the 2 parasinusal implants on the left is mesial; the other is inserted into the tuberosity and not bent.
Figure 17. Circular maxillary metal-ceramic prosthesis; mandibular overdenture. Figures 18–20. Palatine implants. Note their slope and bending.
Fixed metal-ceramic prosthesis in zones 2.4, 2.5, and 2.6.
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