Istvan Urban - Vertical 2 - The Next Level of Hard and Soft Tissue Augmentation

Figs 1-36 and 1-37 A well-adapted dense and perforated membrane showing minimal soft tissue ingrowth.

Fig 1-38 The membrane showed excellent performance in terms of clinical results as well as adaptability and retrievability.

Fig 1-39 Cross-sectional view of the osteocalcin (OCN) marker. The squares demonstrate the regions of interest (ROIs) that were investigated.

Fig 1-40 Graph showing the results of the OCN marker for the three groups investigated.

Fig 1-41 Cross-sectional view of the alkaline phosphatase (ALP) marker. The squares demonstrate the ROIs that were investigated.

Fig 1-42 Graph showing the results of the ALP marker for the three groups investigated.

Immunohistochemistry was also performed, looking at different markers. Of these markers, two demonstrated significantly better results. Osteocalcin (OCN – a marker for osteoblastic activity and level of mineralization) and alkaline phosphatase (ALP – a marker for osteoblastic activity and bone formation) had a significant presence ( Figs 1-39to 1-42).

Figs 1-43 BMP-2/xenograft: Sandwich configuration showing how the BMP-2 is sandwiched inside the xenograft particles (arrow).

Fig 1-44 BMP-2/xenograft: Lasagna configuration showing how the BMP-2 is layered on top of the graft and just below the perforated PTFE membrane (arrow).

These results indicate that the perforated group is more vascularized and has a more active formation. However, the collagen membrane coverage did not seem to be a prerequisite. In fact, the collagen membrane group demonstrated slightly worse results than the group without coverage. This was due to the collagen membrane of choice producing some inflammatory response. It is very likely that the other native type of collagen membranes could help in reducing soft tissue ingrowth. For this reason, the author uses a collagen membrane in conjunction with a perforated PTFE membrane.

This investigation looked at whether the use of a perforated membrane could result in faster and better bone formation with a microdose of osseoinductive stimuli.

In these cases, < 100 µg BMP-2 was used, either inside the graft or just simply placed on top of the graft. The former is called the Sandwich technique and the latter the Lasagna technique. A pure xenogenic bone graft was used. The layered BMP-2 (Lasagna) developed excellent bone formation, which was better than the internally placed BMP-2 (Sandwich) graft, which failed to form a complete ridge (specifically in the middle of the ridge). Even though the Lasagna configuration only had BMP-2 placed on top of the graft, the bone was more evenly formed throughout the entire new ridge. This investigation again demonstrated the importance of the periosteal connection, especially with a growth factor. Note that the Lasagna configuration resulted in excellent new ridge formation throughout the entire ridge ( Figs 1-43and 1-44).

The final case demonstrates the Lasagna technique, where a low dose of BMP-2 was used on top of the graft to improve and accelerate the bone formation ( Figs 1-45to 1-49). Note the complete vertical bone regeneration and the excellent bone quality with minimal smear layer that was regenerated.

Fig 1-45 Labial view of an advanced vertical defect.

Fig 1-46 A 1:1 ratio of autogenous bone mixed with ABBM is used.

Fig 1-47 A BMP-2–infused collagen membrane is layered on top of the graft (Lasagna technique).

Fig 1-48 A perforated dense PTFE (d-PTFE) membrane is used to immobilize the graft.

Fig 1-49 Labial view of the ridge after 9 months of uneventful healing.

The perforated membrane shows that the clinician may expect better bone quality and faster bone formation. It also sheds light on how to use growth factors. Autogenous particulated bone has several growth factors such as BMP-2 and transforming growth factor beta 1 (TGF-B1), hence these results can likely be applied to the autograft/xenograft mixture that is used throughout this book. In some cases, the author has used the Lasagna type of graft with excellent results.

It is also clear that the periosteum should not be blocked, and if a collagen membrane is used, it should be a native collagen membrane that resorbs as rapidly as possible. Crosslinked collagen membranes should not be used over perforated PTFE membranes. Also, particulated bone chips may release more BMP-2 than an autogenous cortical block.

1. Urban IA, Montero E, Monje A, Sanz-Sánchez I. Effectiveness of vertical ridge augmentation interventions: a systematic review and meta-analysis. J Clin Periodontol 2019;46(suppl 21):319–339.

1. Urban I, Baczko L, Parkany I, Coelho P, Tovar N, Nagy K. Dense versus perforated PTFE membranes using BMP-2 grafting [in progress].