https://onlinelibrary.wiley.com/doi/epdf/10.1002/ccr3.3626 Open Access article

Tunkel J, de Stavola L, Kloss-Brandstätter A. Clin Case Rep. 2020;00:1–13. https://doi.org/10.1002/ccr3.3626

The goal of the study was to examine retrospectively if an augmentation with allogeneic bone plates using the shell technique allows vertical and horizontal bone gains comparable to gains achieved with autogenous bone plates.

Material and Methods:

This case series is a retrospective examination of five patients who had a bilateral bone defect requiring verticalaugmentation (three patients) or three-dimensional horizontal augmentation in a buccal and oral orientation (two patients). The augmentations were performed using the shell technique. Due to the size of the defects, the augmentations could not be exclusively performed using the material available from a sole intraoral harvesting site orpatients opted to rectify the bone deficit by allogeneic bone plates (maxgraft® cortico). In total, two CBCTs were recorded for each patient, one before treatment and one directly before implantation. At each time point, the alveolar bone levels were measured in their height, width, and depth at the planned site of the mesial implant, at the site of the distal implant and in the center of the two planned positions. At the other time points, the measurements were taken with a reference template and a caliper. After exposure of the bone, the horizontal width of the alveolar ridge was measured at two positions with a caliper: at the planned site of the mesial implant and at the site of the distal implant.

Major results:

• Uneventful healing in each patient, both on the allogeneic and autogenous augmentation sites.
• Follow-up time of 12 months
• The average horizontal gain was 5.8 ± 0.4 mm on the autogenous side and 6.1 ± 0.6 mm on the allogeneic side, with no difference in the horizontal gain between autogenous and allogeneic sides (Mann-Whitney U test; P = .310).
• At implantation, there were no differences in the horizontal bone gain and resorption rates between the autogenous and allogeneic sites (Mann- Whitney U test; P = .841)
• The average vertical gain was 3.9 ± 1.3 mm on the autogenous site and 3.2 ± 0.3 mm on the allogeneic site, with no difference in the vertical gain between autogenous and allogeneic sides (Mann-Whitney Utest; P = .700).
• There were no differences in the vertical bone gain and resorption rates between the autogenous and allogeneic sides (Mann-Whitney U test; P = .700).

Conclusion:

Both augmentation materials led to equivalent bone gains. By means of the shell technique equal horizontal and vertical bone gain with both autogenous and allogeneic bone plates is achievable.

The additional implementation of augmentative relining with a xenogeneic bone substitute material (cerabone®) and collagen membrane (Jason® membrane) seemed to minimize resorption processes and to maintain bone volume in the long term.

Jochen Tunkel