Horizontal and Vertical Defect Management with a Novel Degradable Pure Magnesium Guided Bone Regeneration (GBR) Membrane-A Clinical Case

Abstract

Background and objectives: In guided bone regeneration (GBR), large defects comprising both horizontal and vertical components usually require additional mechanical support to stabilize the augmentation and preserve the bone volume. This additional support is usually attained by using non-resorbable materials. A recently developed magnesium membrane presents the possibility of providing mechanical support whilst being completely resorbable. The aim of this case report was to describe the application and outcome of the magnesium membrane in combination with a collagen pericardium membrane for GBR. Materials and methods: A 74 year old, in an otherwise good general health condition, was presented with stage 2 grade A periodontitis and an impacted canine. After extraction of the impacted canine, a defect was created with both vertical and horizontal components. The defect was augmented using the magnesium membrane to create a supportive arch to the underlying bone graft and a collagen pericardium membrane was placed on top to aid with the soft tissue closure. Results: Upon reentry at 8 months, complete resorption of the magnesium devices was confirmed as there were no visible remnants remaining. A successful augmentation outcome had been achieved as the magnesium membrane in combination with the collagen membrane had maintained the augmented bone well. Two dental implants could be successfully placed in the healed augmentation. Conclusions: In this case, the magnesium membrane in combination with a collagen pericardium membrane presented a potentially viable alternative treatment to titanium meshes or titanium-reinforced membranes for the augmentation of a defect with both horizontal and vertical components that is completely resorbable. It was demonstrated that it is possible to attain a good quality and quantity of bone using a resorbable system that has been completely resorbed by the time of reentry.

Keywords: bone regeneration; magnesium; periodontal diseases.

Figure 1

(a) Initial X-ray demonstrating peripheral bone loss to the first premolar 24. (b,c) cone beam computed tomography (CBCT) demonstrating severe bone loss around 24 and the positioning of the impacted canine 23.

Figure 2

Augmentation of the bony defect. (a) Initial clinical situation, (b) bone defect after the extraction on 23 and 24, presenting a vertical and horizontal component, (c) application of the bovine bone graft, (d) placement of the magnesium membrane, cut into a rounded strip and bent over the defect to provide a supporting arch, (e) positioning of a pericardium membrane, (f) first intention closure, (g) healed site at 8 months.

Figure 3

Reentry at 8 months, (a) control periapical X-ray, presenting good maintenance of bone volume, (b) flap elevation for implant placement, (c) implant placement, (d) non-submerged healing with the application of healing screws.

Figure 4

Optical impressions for completion of the final prosthesis.

Figure 5

Application of final prosthesis, (a) a screw retained three-unit bridge made of monolithic zirconia, (b) final appearance of augmented site, (c) applied bridge, (d) control X-ray, (e) final aesthetics from the buccal view.

Figure 6

Comparison of periapical X-rays during different phases of the treatment, (a) the initial situation, (b) control X-ray at 8 months, prior to reentry, (c) post operative X-ray after implant placement.