A Simplified Bone Regeneration Technique for Implant Placement Using a Titanium Membrane

The use of dental implants offers an affordable and predictable method for replacing missing teeth, yielding satisfactory clinical outcomes over the long-term. Several studies emphasize the importance of the presence of marginal bone stability following implant placement as a notable contributing factor to this long-term success and the overall predictability of dental implants and propose a recommended minimum of 2 mm of bone to achieve this stability.^1,2 However, due to the multifaceted etiology and increased incidence of bone loss, this minimum bone level requirement is often not met and, in many cases, regenerative procedures, such as hard-tissue grafting, are required to reconstruct the alveolar process prior to implant placement.

Over the years, various protocols and techniques have been proposed for hard-tissue grafting. These include guided bone regeneration using resorbable and nonresorbable membranes, autogenous bone grafting,³ titanium mesh utilization,^4,5 and, most relevant to this article, the use of titanium membranes attached to the implant and/or abutment.^6,7

Currently, there are two titanium membrane systems known to be available on the market (i-Gen, Megagen, megagen.com; OssBuilder, Hiossen/Osstem, hiossen.com).^8,9 Both of these systems feature three basic components: a titanium membrane, an abutment to support the titanium membrane, and a screw to secure the titanium membrane in place with respect to the abutment.

The titanium membrane component of these systems is available in different shapes and sizes designed for specific clinical situations, allowing users to select the most appropriate one for each individual case. However, the membranes can be difficult to shape, trim, and/or bend due to their specifications and thicknesses. This can limit the amount of customization to the membrane system that may be needed to accommodate the many different clinical situations clinicians encounter.

To overcome this limitation, the author aimed to develop a single abutment with a simplified titanium membrane that can be customized for use in various clinical situations, thereby providing an alternative solution for cases unsuited to the discretely shaped/sized options currently available (Figure 1).

A 64-year-old woman was referred for the replacement of a failing maxillary right canine, which had previously undergone endodontic treatment and restoration with a metal post-core and crown. A comprehensive patient history was taken, and a clinical and radiographic examination was conducted.

The patient's history revealed that she was a former smoker and was currently undergoing treatment for previous transient ischemic attacks and Parkinson's disease. Her medication regimen included apixaban, bisoprolol, atorvastatin, mirapexin, Sinemet^®, and Accrete D3^®. Additionally, the patient reported an allergy to trimethoprim/sulfamethoxazole, regular visits to the oral hygienist, and no signs of periodontal disease.

Upon examination, the failing tooth No. 6 exhibited mobility, which was confirmed by a CBCT scan. The tooth was fractured just below the gum line, with a small periapical lesion and significant bone loss observed in the mesial-buccal area (Figure 2 through Figure 4).

As part of the treatment plan, the failing tooth was scheduled for extraction, followed by an immediate implant placement protocol. Because of the existing bone loss in the area, it was recommended that the patient also undergo bone regeneration to promote a successful outcome. The available regenerative options were discussed in detail, and the patient and clinician agreed on the use of the aforementioned abutment with a customizable titanium membrane. Informed consent was then obtained from the patient.

Prior to the start of the surgical procedures, venous blood was collected from the patient and centrifuged according to the advanced platelet-rich fibrin (A-PRF) protocol (Choukroun's process for PRF) for use in the grafting procedure.¹⁰

The failing tooth was extracted atraumatically under local anesthesia, whereby a full-thickness flap was raised and the area debrided (Figure 5). The osteotomy was prepared using various osseodensification burs (Densah^®, Versah, versah.com) under saline irrigation in preparation for placement of the implant (Deep Conical [DCT], Southern Implants, southernimplants.com) (Figure 6).

After implant insertion (insertion torque ≥40 Ncm), the abutment was attached to the implant and torqued to 20 Ncm². The titanium membrane, designed by the author, was then trimmed, manually shaped, and the edges gently bent inward toward the bone using surgical scissors and a needle holder (Figure 7). The final shape of the titanium membrane allowed between 3 mm and 4 mm of space between the surface of the bone and the membrane. This was to account for an optimal 2 mm of future bone growth around the implant as well as for the production of a pseudo-periosteum by the surrounding tissue.^11,12

Once the optimal membrane shape was obtained, grafting material consisting of allograft (MinerOss^® Blend cortico-cancellous, BioHorizons, biohorizons.com),¹³ standard PRF (S-PRF), and A-PRF was inserted into the area (Figure 8), and the titanium membrane was placed and secured using a screw (Figure 9). The flaps were then released, and the area covered with two A-PRF membranes (Figure 10).

Routine clinical and surgical assessments were conducted at 2 weeks and 6 weeks post-surgery. At the 3-month follow-up, the titanium membrane and abutment were removed, a healing abutment was placed, and the patient was referred for restorative work (Figure 11 and Figure 12). Additionally, the patient was seen by an oral hygienist and reviewed by a lead surgeon every 4 and 6 months, respectively, following surgery (Figure 13). CBCT scans were taken at various timepoints, including directly after implant placement (Figure 14), at the 1-year follow-up (Figure 15 and Figure 16), and at the 2-year follow-up (Figure 17). These scans demonstrated stable bone levels and acceptable levels of bone remodeling at up to 2 years post-implant placement.

The case presented represents the oldest of 28 cases treated to date using the abutment and customizable titanium membrane designed by the author. The thickness of the titanium membrane used provides sufficient rigidity and minimal elasticity while allowing easy trimming with a pair of scissors and bending. The results of this case appear to be stable, both clinically and radiologically. This is in agreement with findings observed in the other cases treated by the author. Complications observed in these cases have included titanium exposure with minimal graft loss and implant failure without graft loss.¹⁴ In cases with titanium exposure, the patients were advised to maintain a high level of oral hygiene and the titanium membrane and associated abutment were removed. No other complications were identified.

Other authors have observed similar and comparable results with the use of titanium mesh/membranes and other grafting methods.^7,15 Additionally, similar clinical outcomes have been observed when titanium mesh/membranes are used alone and in combination with resorbable membranes.^16-18

Based on the results of this case study and the experience of the author, the combination of grafting and placing an abutment-associated titanium membrane provides a viable alternative with stable outcomes when used as part of dental implant placement for patients who present with bone loss. This alternative method allows for customization for individual clinical situations and reduces the need for differently shaped/sized membranes. It can simplify the surgical procedure, thereby reducing the surgical times and associated costs. The nature of this single case report presents limitations to these conclusions, and a well-designed, prospective study is required to investigate the efficacy and viability of this treatment option in greater detail.

Stavros Eleftheriou, DDS
Private Practice in Oral and Maxillofacial Surgery, Winchester, Hampshire, United Kingdom; Honorary Lecturer, Queen Mary University of London, Institute of Dentistry, London, England